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In this work, the adsorption structure of deuterated water on the stepped platinum surface is studied under an ultra-high vacuum by using heterodyne-detected sum-frequency generation spectroscopy. On a pristine Pt(553), D2O molecules adsorbed at the step sites act as hydrogen bond (H-bond) donors to the adjacent terrace sites. This ensures the net D-down orientation at the terrace sites away from the steps. In particular, the pre-adsorption of oxygen atoms at the step sites significantly alters the D-down configuration. The oxygen pre-adsorption leads to a spontaneous dissociation of the post-adsorbed water molecules at the step to form hydroxyl (OD) species. Since the hydroxyl at the step acts as a strong H-bond acceptor, D2O at the terrace no longer maintains the D-down configuration and adopts flat-lying configurations, significantly reducing the number of D-down molecules at the terrace. Density-functional theoretical calculations support these pictures. This work demonstrates the critical role of steps in controlling the net orientation of the interfacial water and provides an important reference for future considerations of the reactions at electrochemical interfaces. [ABSTRACT FROM AUTHOR]

The practical use of 4H-SiC as a semiconductor material alternative to Si has been investigated by several researchers. However, a key challenge impeding its practical implementation is the elimination of killer defects in the epitaxial layer, such as basal plane dislocations (BPDs), which cause bipolar degradations. The conversion of BPDs into threading edge dislocations is crucial to reduce detrimental mobile dislocations. However, their underlying atomistic mechanisms remain unclear. In this study, the effects of the step height and distance from the step on the contraction of BPDs were determined using a reaction pathway analysis. Notably, the step height did not affect the contraction, and the activation energies for the contraction of the partial dislocation pairs with Burgers vectors closed toward the step were 0.4 (C face) and 0.3 eV (Si face) lower than those for expansion. Conversely, for the partial dislocation pairs with Burgers vectors open toward the step, the activation energies for contraction were 0.4 (C face) and 0.2 eV (Si face) higher than those for expansion. Furthermore, the effect of the step diminished when the distance from the step exceeded 3 nm. The results suggest that the steps prevented contraction, and longer terraces reduced this preventive effect. Therefore, a surface morphology with fewer steps and longer terraces would increase the conversion rate. Furthermore, a low-off-angle substrate and surface polishing would increase the conversion rate, whereas step bunching slightly would decrease it. Macrosteps would decrease the conversion rate as the average distance from the surface to BPDs increased. [ABSTRACT FROM AUTHOR]

The paper discusses the research and methodological aspects of introducing the new term "catafluvial deposits" into genetic classification of Quaternary deposits. For this purpose, fieldwork was carried out aimed at studying terrace complexes within the Yaloman-Katun zone of Gorny Altai, which has recently become a unique natural laboratory for investigating hypothetical glacial superfloods. Based on original materials and data from other areas with similar geological and physico-geographical conditions, it is concluded that the introduction of a separate genetic type "catafluvial" is currently premature. [ABSTRACT FROM AUTHOR]

Copyright of New Architecture is the property of New Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A comprehensive examination of uplifted mid-late Pleistocene marine terraces along the eastern coast of Korea offers valuable insights into the temporal and spatial variability of uplift rates spanning ∼200 ka. Focusing on the Gangneung–Samcheok region of the Korean peninsula's east coast, the study area is delineated into three distinct areas (i.e., Anin, Jeongdongjin–Donghae, and Samcheok) by two NNE-SSW to NE-SE-striking faults. Three flights of marine terraces are developed in each area, with terraces typically observed at elevations of 10 to 20 m and 20 to 35 m across all three areas. Conversely, upper terraces exceeding these elevations are mainly observed at 50 to 60 m or 60 to 80 m, with regional variations noted. Quartz optically stimulated luminescence dating (OSL) was used for dating marine terrace deposits. However, it could not be applied to older deposits beyond the upper limit of quartz OSL. Therefore, IRSL and post IR-IRSL dating using K-rich feldspar, which has a higher upper limit than quartz OSL, were applied in this study. The results indicate that marine terraces at elevations of 10 to 20 m and 20 to 35 m formed during MIS 5a and MIS 5e. Depositional ages of MIS 7 were obtained from terraces ranging from 50 to 60 m or 60 to 80 m, exhibiting elevation differences across regions. Consequently, the estimated temporal variation in uplift rates revealed an average uplift rate of 0.52–0.79 m/ka from MIS 7 to MIS 5e, followed by 0.2–0.3 m/ka after MIS 5e. Spatial variation in uplift rates was observed from MIS 7 to MIS 5e. Specifically, the uplift rate in the Jeongdongjin–Donghae area, located in the middle part of the study area, was 0.79 m/ka (Min. 0.68 m/ka, Max. 0.90 m/ka), whereas the uplift rate in the other study areas was 0.52 m/ka (Min. 0.41 m/ka, Max. 0.62 m/ka). This discrepancy is probably attributed to the influence of the two faults that subdivide the study area. [ABSTRACT FROM AUTHOR]

Copyright of Materiały Budowlane is the property of Wydawnictwo SIGMA-NOT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article is devoted to the study of a class of reaction-advection-diffusion equations of the form u t − Δ u + β (y) u x = f (t , u) in cylinders, where f is a tristable or multistable nonlinearity satisfying f (⋅ , 0) = f (⋅ , 1) = 0. We establish the alternative of wave solutions, that is, either there is a unique, asymptotically stable periodic traveling wave connecting 0 to 1 directly, or there is a unique propagating terrace connecting 0 to 1. Under the assumption that all wave speeds in propagating terrace are not equal to each other, we further obtain that the propagating terrace is asymptotically stable if it exists. Moreover, the sufficient and necessary conditions for the existence of periodic traveling waves connecting 0 to 1 are given respectively. Our arguments are based on the parabolic maximum principle, sliding method and the super- and sub-solution method. [ABSTRACT FROM AUTHOR]

This study used sedimentary archives obtained from a high-standing terrace along the coastal zone of the Coquimbo region to reconstruct past extreme events (floods and tsunamis). Using sedimentological (grain size), geochemical (XRF), and geochronological (14C and 137Cs) analyses, we identified nine flood deposits (1957, 1965, 1984, 1987, 1991, 1997, 2002, 2015, and 2017) and one tsunami deposit (1922). The sedimentary flood record appears complete for the last 70 years and is useful for reconstructing paleoflood events, highlighting the relevance of coastal high-standing terraces to improve our understanding of the frequency of floods in Chilean coastal areas. [ABSTRACT FROM AUTHOR]

The purpose of the study was to develop a manually operated maize planter cum vermicompost applicator for narrow terraces of Sikkim. For the timely operation with less effort and drudgery, a lightweight manually operated planter cum vermicompost applicator is required for the uneven topography and small terrace. Three commonly grown varieties of maize (i.e. sethi makai, pahelo makai and rato makai) were used. The mean values of length, width, thickness, geometric mean diameter, sphericity and roundness of three varieties maize were determined for designing the cell size of metering drum. Laboratory test was conducted to optimize the operating parameters of manually operated maize planter cum vermicompost applicator. Optimum performance of the planter was recorded with cell size of 11 mm and 25 % hopper fill level. Furthermore, the planter was operated in the field and also compared with the traditional planting. Average heart rates while operating manually operated maize planter cum vemicompost applicator and traditional planting, were recorded as 114 and 126 bpm respectively. The BPDR experienced maximum in both cases but traditional planting observed extreme pain in backbone due to continuous bending posture. The ODR was found to be higher in traditional planting ranges from 7 to 8 whereas manually operated maize planter cum vermicompost applicator ODR was found in the range of 4 to 5. [ABSTRACT FROM AUTHOR]

Reconstruction and rehabilitation have gone through a long period, and now in its latest version, experts have considered regeneration as a comprehensive solution. A kind of improvement that not only seeks to improve the physical space but also considers the social, cultural, economic, and other aspects of such issues in the field as well as the surrounding areas. In this research, the concept of urban regeneration and in particular, urban regeneration in France and the city of Paris, in the "Beaubourg" neighborhood has been discussed and the pillars of the success of the urban regeneration project of this neighborhood have been studied. The neighborhood, which has now become one of the best-known neighborhoods of the city through the "George Pompidou Center", was one of the less developed neighborhoods of Paris in the past. This part of the research is a descriptive-analytic study whose theoretical data have been collected through library studies and in the section of collecting information about the current situation of the neighborhood through direct field observation. Then, following the process of follow-up studies, the weaknesses of this plan were identified using a creative problem-solving process. Considering that the authors of the article were not native and had a new look at the objective structure of the neighborhood, finding weaknesses that were hidden from the French resident observer was on the agenda, and the western front of the Arsene of "Saint-Merry" cathedrals courtyard, was identified as a weak point of the Beaubourg neighborhood regeneration project. To continue the process of recreating and extending its success to the identified weak point, a research process and development have been pursued to provide practical solutions. In the final result and presented solutions, the concept of "Terrace", as the most important pillar of the success of the Beaubourg neighborhood regeneration project, has been the authors' work tool. [ABSTRACT FROM AUTHOR]

The innovation of 3D FinFETs using top‐down silicon nanofins represents a significant advancement toward scaling down microchip process nodes to the cutting‐edge 3‐nm level. While bottom‐up semiconductor nanofins also hold promise as building blocks for FinFETs, their controlled growth remains challenging. Drawing inspiration from the guided roots along brick gaps, this study shows that the aligned atomic terraces on an annealed miscut LaAlO3 surface can trigger an exceptional graphoepitaxial effect, encouraging the bottom‐up vapor‐phase growth of self‐aligned nanostructures such as CdS, CdSe, ZnSe, and ZnTe. Subsequently, the resultant CdS nanofins, characterized by narrow widths of ≈20 nm and large height‐to‐width ratios exceeding 16, can be seamlessly assembled into arrayed FinFETs on the insulating LaAlO3 substrate, obviating the need for post‐growth alignment steps. Unlike most nanostructure‐based planar transistors, which often operate in depletion mode characterized by negative thresholds, these FinFETs operate in enhancement mode with positive thresholds (≈5 V), ≈10−14‐A standby currents, and ≈108 on/off current ratios. The achieved ratio surpasses the record for planar enhancement‐mode CdS transistors by 4 orders of magnitude, primarily due to the enhanced electrostatic control over the nanofins. Overall, the graphoepitaxially side‐by‐side nanofins show tremendous potential to expand the repertoire of FinFETs based on non‐silicon semiconductors. [ABSTRACT FROM AUTHOR]

Since the mid-1990s, a hermeneutic struggle has unfolded within English football between those spectators who wish to stand at matches, and the 'risks' associated with this practice. Here, the authorities have sought to constrain this form of leisure through an anti-democratic, authoritarian regime of discipline and control. By designating the ritual of standing as 'a right to leisure', however, this article draws upon radical democratic theory to re-imagine this practice as a contested activity; one which has the potential to challenge the neoliberal basis of football spectatorship itself and restore the collectivism that was a much-loved feature of the terraced community. By restating the social value of free-standing terraces, and the potentialities that standing itself offers for political emancipation, we argue that this ritual might itself become a rights-based resource of radical democracy for spectators to engage in an altogether more participatory form of leisure. [ABSTRACT FROM AUTHOR]

The Daliangshan region (DLS) is characterized by significant vertical differentiation in human activity and land use owing to the high elevation gradient, which may affect the soil erosion pattern in the vertical direction. However, the spatial variability of soil erosion rates along a hillslope at the catchment scale remains poorly understood. In this study, we used the cesium‐137 tracer technique to estimate soil erosion rates under different land uses and vertical zones from a small agricultural catchment, the Luowugou catchment in the DLS. Ten plots comprising four typical vertical zones (valley, low mountain, middle mountain and sub‐alpine) and five land‐use types (sloping farmland, grassland, abandoned farmland, forest land and horizontal terrace) were selected. In addition, two parallel downslope transects were built in each plot, and soil samples were collected at 3–7 m intervals along these transects. The results indicated that the soil erosion rates on sloping farmland (4.82 kg·m−2·y−1) and grassland (4.09 kg·m−2·y−1) were significantly higher than those on abandoned farmland (0.91 kg·m−2·y−1) and forest land (0.80 kg·m−2·y−1). In contrast, the horizontal terrace showed net deposition, with a deposition rate of 0.62 kg·m−2·y−1. The erosion rates varied across different zones, with the low mountain zone having the highest erosion rate (5.65 kg·m−2·y−1), followed by the middle mountain (2.96 kg·m−2·y−1) and subalpine (1.46 kg·m−2·y−1) zones, and the valley zone having the lowest erosion rate (1.28 kg·m−2·y−1). Furthermore, there were significant correlations (P < 0.05) between the soil erosion rates from different vertical zones and the proportion of sloping farmland, implying that sloping farmland plays a dominant role in shaping soil erosion along a vertical gradient. These comparisons suggest that the highest soil erosion rate occurred in the low mountain zone, indicating that the steeply sloping farmlands, resulting from migration from high‐altitude areas, have intensified soil erosion in the vertical zone. These findings highlight the role of agricultural activities originating from sloping farmlands in influencing soil erosion across different vertical zones, which has important implications for mitigating soil erosion and optimizing agricultural layout in the region. [ABSTRACT FROM AUTHOR]

In this paper, we review current understandings of anthropogenic field systems, focusing on trends and variations in the chronology of field construction, use, and in some cases, abandonment, as well as labor organization of agrarian production across the Lake Titicaca Basin. These trends indicate that agricultural intensification increased both during the political centralization of the Tiwanaku state and during periods of political fragmentation. In contrast to prior work on fields in the region, we argue that there was no single cultural, environmental, or historical impetus that ignited the construction of any particular field type. Additionally, we present the results of pedestrian survey of terraces carried out in 2018 in the northern Lake Titicaca Basin. While there were regional commonalities across survey areas in the masonry design of terrace risers, presence of pathways and radiating walls separating vertical tracts of terraces, and a general absence of irrigation, we found deviations from each of these trends in individual terrace complexes. While preliminary evidence indicates that more terraces were built or cultivated during the Late Intermediate period (1100–1450 CE) than in other time periods in the northern Titicaca basin, some terraces were likely built earlier. Our findings point to the multiplicity of strategies that ancient farmers employed in the varied ecological settings of the Lake Titicaca basin under diverse sociopolitical programs. This contrasts with previous research on agrarian field systems, which is mostly single‐sited and tends to emphasize individual strategies over the quiver of agrarian options available to Andean farmers. [ABSTRACT FROM AUTHOR]

Forest terracing operations imply a massive mobilization of topsoil. Nonetheless, its impacts on soil properties, functions and ecosystem services have been poorly quantified so far. Therefore, this study aimed to explore how bulldozer bench terracing may impact the abundance and diversity of ground-dwelling arthropod communities of eucalypt plantations. To this end, three neighbouring sites were selected of which one had not been terraced a –(NT), one had been terraced recently (two months earlier; -RT) and one had been terraced more than a decade (14 years ago; OT). The exploratory nature of this study involved furthermore a single sampling occasion (during spring), and taxonomic identification till the level of order and, in the case of the most frequent orders, (sub-)family. The arthropod communities of the RT site and the NT site did not reveal significant differences in terms of either total abundance or order richness, suggesting that immediate effects of terracing on these aspects of biodiversity may be limited. Nonetheless, notable differences did exist between these two sites for two out of the three prevailing orders. Araneae occurred with a markedly lower abundance as well as family richness at the RT site than at the NT site, while the opposite was true for the Coleoptera, at least in terms of family richness. The communities of the RT site and the OT site also did not evidence substantial differences in abundance or order richness, indicating that terracing effects on these aspects may not increase with time-since-terracing. In fact, the opposite was suggested, since none of the three prevailing orders revealed significant differences in abundance or richness between the two sites. In spite of the reduced effects observed here of massive soil mobilization by bulldozer terracing, further research is plainly justified not only because of the exploratory nature of this study but also the widespread bench terracing in the study region. The present results suggested that such further research should focus on the impacts during the first decade. [ABSTRACT FROM AUTHOR]

The evolution of the Jinshan Gorge in the middle reaches of the Yellow River in China has long been a topic of debate. Previous studies have primarily focused on the connection between the Sanmen Gorge and Jinshan Gorge, attributing this connection to the Yellow River's carving through the pre‐Cenozoic bedrock areas of the Sanmen Basin. However, the patterns of knickpoint propagation along the river, influenced by tectonic upheaval and base‐level changes, have yet to be explored, despite their potential to understand fluvial system and canyon evolution. In this study, we address this issue by employing forward and inverse numerical modelling of longitudinal profiles of the Jinshan Gorge of the Yellow River and its tributaries and correlating the river terraces in this reach. We investigated 18 terrace profiles to explore their formation processes. The results demonstrated that the steepness index (Ksn) values and the incision rates of tributaries increase downstream, aligning with the relationship between knickpoint elevation and proximity to the Hancheng Fault. The knickpoint propagation appears to be related to the tectonic activities of the Hancheng Fault before 130 ka and then was influenced by climatic change, resulting in the development of five‐stage knickpoints (named Kp1, Kp2, Kp3, Kp4 and Kp5 from old to young) that correlate with the formation of terraces in the downstream area. We calculated the formation ages of Kps 1–4 to be 1.59 ± 0.06, 0.94 ± 0.11, 0.57 ± 0.31 and 0.22 ± 0.14 Ma, respectively. Kps 1, 2 and 4 correspond to the formation of the Yellow River terraces with the ages of 1.24, 1.12 and 0.24 Ma, which were reported previously. The formation of the oldest knickpoint can be correlated to the establishment of the modern course of the Yellow River in this region, which is deduced to be ~1.59 Ma. [ABSTRACT FROM AUTHOR]

In mountain belts, strath terrace staircases serve as markers for deriving river incision rates and erosional patterns. Distinguishing between terrace patterns influenced by external perturbations like changes in climate and tectonics and those driven by internal dynamics including feedbacks between topography, erosion and sediment transport remains challenging. We demonstrate that in a collisional mountain belt, lithology can act as a first‐order control on the spatial and temporal scales of strath terrace formation. Here, we investigate the role of lithology in modulating internal dynamics and the formation of strath terraces in the Mgoun River catchment of the High Atlas in Morocco, a region characterised by constant low‐rate rock uplift, a cyclical cool‐warm/arid‐humid Quaternary climate history and contrasting bedrock lithologies. By collecting (1) modern river and terrace clast data, (2) bedrock strath and strath‐top sediment elevations of four terrace levels, (3) terrace sedimentology and (4) integration with published terrace chronology, we found a dominance of local sediment input from hillslopes, mostly from recycled bedrock conglomerates. Additionally, we found valley width, controlled by the stratigraphic and structural configuration of lithological erodibility, significantly impacts sediment connectivity. The isolation between valleys with varying widths results in varied timescales of river channel response to hillslope coupling, with hillslope‐derived stochastic sediment gravity flows preserved in fluvial terraces in some river reaches and not in others. Furthermore, asynchronous terrace formation and abandonment ages result from the low longitudinal river connectivity between multiple valleys formed in erodible rock separated by gorges in high‐strength rock. These gorges limit knickpoint migration rates, inhibiting the ability of terraces formed in one valley to spread through the catchment. These findings can inform future research distinguishing between autogenic and external signals in erosional landscapes and help carefully derive river incision rates and climate insights from terraces. [ABSTRACT FROM AUTHOR]

The main assumption of the text is that, in Poland, small fan groups are facing a threat to their existence, and many of them are functioning in an evident crisis. Based on secondary data, the main mechanisms influencing the problems of fan groups from smaller clubs in maintaining and developing their potential will be reconstructed. These mechanisms are: economic emigration of supporters, ageing of supporter group members (lack of generational replacement), 'old-fashioned' style of supporting based on violence and aggression, the changing attitude of the young generation to spend free time and decreasing interest of young people to participate in fan culture, lack of sporting success of clubs, lack of fan rivals in low-level football leagues. The article concludes that in the near future, the number of fan groups of small clubs will drastically decrease, and the whole fan culture in Poland will face crisis and uncertainty. [ABSTRACT FROM AUTHOR]

A study of the valley topography of the northeastern part of Terra Cimmeria on Mars was carried out. The results of the study allow us to draw the following conclusions. (1) The morphology of the studied valley systems corresponds to their presumed fluvial origin. (2) The remains of the paleodelta in the Gusev crater, fragments of terrace levels traced along the valley, regular changes in their height, as well as the remains of eroded accumulative bodies discovered in the Ma'adim Valley indicate the existence of individual episodes of partial filling of the valleys with sediment, probably due to the activation of the uppermost links of the valley system that supplied fragmentary material to the main valley. A detailed study of the morphology and topography of the Durius Valley suggests the same mechanism of its formation. [ABSTRACT FROM AUTHOR]

This article explores the relationship between Alain Locke, an African American philosopher, and the Bahá'í faith. It discusses Locke's visit to Haifa in 1923, where he met with Shoghi Effendi, the Guardian of the Faith. The article examines whether Locke was a devout believer in the Bahá'í faith or if his philosophical views were incompatible with it. The author argues that Locke's commitment to Bahá'í principles and his spiritual sensibility make him a Bahá'í, even if he did not hold doctrinaire beliefs. The article also reflects on the author's visit to the Terraces of the Shrine of the Báb in Haifa, Israel, and discusses the ongoing conflict and segregation in the region. The author concludes by expressing their own perspective as an atheist and realist, appreciating the spiritual value of the garden while acknowledging the tragic nature of the world. [Extracted from the article]

From the start of river incision onward, the abandoned terrace surface is only reached by floods during peak discharges. Two main flood facies are distinguished: a relatively high-energetic, coarse-grained facies and a relatively low-energetic, fine-grained facies. In general, the flood deposits become gradually finer-grained and the finer-grained facies relatively more prominent when the river incises progressively deeper. This signifies a delayed and prolonged effect of channel incision and flood deposition compared with the climate changes that initiated the incision. However, these long-term trends may be interrupted by shorter-term events of flooding or non-deposition. Those short events are expressed by cycles of coarse-grained deposits from small/shallow flooding channels due to short peak discharges or fine-grained suspended sediment and incipient soils during periods of low flow. These short events may be attributed to short climatic episodes or intermittent intrinsic river evolution. [ABSTRACT FROM AUTHOR]

The widespread adoption of large‐scale machines has led to a significant shift in terrace construction methods, transitioning from manual labor to mechanical processes. Mechanical terracing, by deeply disturbing the surface and compaction of the soil, has resulted in significant variations in both the soil physicochemical properties (SPCs) and soil infiltration properties (SIPs). However, few studies have been carried out to investigate the impact mechanisms of mechanical terracing on soils. In this study, we conducted detailed field experiments to determine the effects of mechanical terracing on SPCs and SIPs. The results showed that mechanical terracing increased soil compaction and decreased soil porosity and organic matter compared to manual terracing. Moreover, mechanical terracing had lower initial and steady infiltration rates than manual terracing (decreasing by 2.60% and 18.59%, respectively). However, initial and steady infiltration rates significantly improved compared to sloped land, increasing by 20.82% and 54.68%, respectively. The partial least squares path model indicated that bulk weight, organic matter content, and soil texture were the dominant influencing factors of SIPs. The results underscore the critical need to incorporate distinctions between various terrace construction methods into hydrological models for more accurate predictions. [ABSTRACT FROM AUTHOR]

Terraces, farmlands built along hillside contours, are common anthropogenically designed landscapes. Terraces control soil and water loss and improve land productivity; therefore, obtaining their spatial distribution is necessary for soil and water conservation and agricultural production. Spatial information of large-scale terraces can be obtained using satellite images and through deep learning. However, when extracting terraces, accurately segmenting the boundaries of terraces and identifying small terraces in diverse scenarios continues to be challenging. To solve this problem, we combined two deep learning modules, ANB-LN and DFB, to produce a new deep learning framework (NLDF-Net) for terrace extraction using remote sensing images. The model first extracted the features of the terraces through the coding area to obtain abstract semantic features, and then gradually recovered the original size through the decoding area using feature fusion. In addition, we constructed a terrace dataset (the HRT-set) for Guangdong Province and conducted a series of comparative experiments on this dataset using the new framework. The experimental results show that our framework had the best extraction effect compared to those of other deep learning methods. This framework provides a method and reference for extracting ground objects using remote sensing images. [ABSTRACT FROM AUTHOR]

Highlights: Terraced lands are a historical landscape under risk in Mediterranean mountains; Their surface and land-use trajectories are analyzed across five centuries in a GIS; Although mostly abandoned, they persist in the ground landscape; Their environmental and productive functions are part of their future resilience. Terraced historical landscapes have multiple functions in mountain land, limiting erosion, enabling agricultural production and constituting cultural heritage. Currently, they are largely abandoned in Mediterranean regions and facing the ongoing impacts of climate change. Our aim is to reconstruct the evolution of land use on the terraces in order to test the hypothesis of the resilience of these landscapes and their age in recent history (17th–21st century). To achieve this, we used various current and archive spatial datasets and GIS knowledge to detect and map terraces and the changes in land use. We tested this hypothesis in a territory impacted by a recent extreme event, facing the challenge of its reconstruction. Our main outcome showed that the optimal use of the terraces corresponded to the demographic optimum of the mid-19th century, and they were gradually abandoned after the Second World War, with significant differences between Mediterranean and mountain lands. Despite this evolution, the terraces persisted and withstood an extreme event, validating our resilience hypothesis and opening avenues for the revitalization of this territory based on this heritage. These findings are drawing perspectives for the future of terraced landscapes in Mediterranean mountains in the context of climate change. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Resources & Ecology is the property of Journal of Resources & Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Questions: Viticulture on steep slopes has shaped the landscape and biodiversity in many regions, but insufficient profitability has led to management cessation and shrub encroachment. A solution to maintain economically viable cultivation could be vineyard terracing. We aimed to identify the potential of terracing to enhance plant diversity and habitat heterogeneity in vineyards, analyze effects of management intensity on vineyard vegetation, and assess how plant communities change after vineyard abandonment. Location: Wine‐growing region of the Upper Middle Rhine Valley in Hesse (50.042342° N, 7.814533° E) and Rhineland‐Palatinate (50.119139° N, 7.719275° E), Germany. Methods: We recorded vascular plant species and local vineyard parameters in vertically oriented vineyards with vegetated and tilled open inter‐rows, in terraced vineyards with tilled terrace inter‐rows and extensively managed embankments, and in vineyard fallows in a total of 45 study sites. We used plant species richness, Ellenberg indicator values and Grime's strategy types to describe how traits and ecological requirements respond to distinct vineyard management. Results: Plant species richness and composition were determined by management‐derived disturbance intensities. Extensively managed embankments had a distinct plant community, the highest plant species richness, more perennial and indicator species, and lower nitrogen indicator values compared with inter‐rows. By contrast, highly disturbed open and terrace inter‐rows revealed plant communities associated with annuals and ruderals, but species richness did not differ between terrace inter‐rows and embankments. The plant communities of fallows were completely different with lower plant diversity. Conclusions: Our results highlight the potential of terraced vineyards for plant diversity with nutrient poor, extensively managed embankments providing conditions that have become rare in modern agricultural systems. A long environmental gradient from terrace inter‐rows to embankments created habitat heterogeneity within a narrow space. By contrast, intensive inter‐row management in vertically oriented vineyards hampers high plant diversity and abandonment fosters the spread of woody species at the expanse of plant diversity. [ABSTRACT FROM AUTHOR]

Changes in land-use practices have been a central element of human adaptation to Holocene climate change. Many practices that result in the short-term stabilization of socio-natural systems, however, have longer-term, unanticipated consequences that present cascading challenges for human subsistence strategies and opportunities for subsequent adaptations. Investigating complex sequences of interaction between climate change and human land-use in the past—rather than short-term causes and effects—is therefore essential for understanding processes of adaptation and change, but this approach has been stymied by a lack of suitably-scaled paleoecological data. Through a high-resolution paleoecological analysis, we provide a 7000-year history of changing climate and land management around Lake Acopia in the Andes of southern Peru. We identify evidence of the onset of pastoralism, maize cultivation, and possibly cultivation of quinoa and potatoes to form a complex agrarian landscape by c. 4300 years ago. Cumulative interactive climate-cultivation effects resulting in erosion ended abruptly c. 2300 years ago. After this time, reduced sedimentation rates are attributed to the construction and use of agricultural terraces within the catchment of the lake. These results provide new insights into the role of humans in the manufacture of Andean landscapes and the incremental, adaptive processes through which land-use practices take shape. [ABSTRACT FROM AUTHOR]

Uplifted Pleistocene marine terrace sequences are used to quantify uplift rates along active margins by knowing terrace age and elevation, and sea level (SL) position at the time of terrace formation. When terraces are undated, ages are assigned by correlating terraces at progressively higher elevations with progressively older highstands. Uplift at convergent margins can be constant over time or occur coseismically during upper plate earthquakes. We explore the formation of terrace sequences under conditions of constant and earthquake‐driven uplift by using a forward numerical model. The modeling reveals that terraces are generally abandoned at SL highstands but they are carved during all stands, depending on the time spent within the sea erosional‐depth‐range. Therefore sea reoccupation of a same platform after formation is a common occurrence that decreases with increasing uplift rates, suggesting that most platforms in nature may be in fact polygenetic. Furthermore, the model run time influences the terrace sequences: terraces formed at the beginning of longer runs constitute an 'inherited morphology' affecting subsequent sequences. When coseismic uplift is applied, the formation and preservation of terraces for a given average uplift rate depend stochastically on the coseismic displacement ‐ recurrence interval combination in relation to the SL position at the time of the earthquake. These factors significantly contribute to a higher likelihood of non‐preserved terraces along a terrace sequence, which may affect age correlation and, consequently, the resulting uplift rates. Further research is needed to explore the effect of the full seismic cycle in shaping a terrace sequence. Plain Language Summary: The topography of the upper plate in a subduction zone is subject to uplift over time. The action of the sea on the coast creates marine terraces, horizontal erosional platforms that, if uplifted, form a staircase morphology. Terrace staircase sequences are used to calculate the average uplift rate of the coast if the terrace age is known. In absence of datable material, the terrace age is inferred by assuming that terraces are preserved in chronological order of formation along the sequence. We use numerical models to explore the generation of subsequent marine terraces forming a staircase sequence on coastal margins subject to constant uplift over time or to instantaneous uplift caused by earthquakes occurring at a certain frequency (recurrence interval). We observe that: terraces are carved as long as they lie within the sea erosional depth; sea reoccupation of previously formed terraces occurs frequently, increasing with decreasing uplift rates; running the model for longer or shorter periods of time has changes morphology of the sequence; varying the earthquake recurrence interval results in different staircase morphologies even if the average uplift rate remains unchanged. The potential absence of terraces increases the chance of assigning, through cross correlation, wrong terrace ages, resulting in inexact uplift rates. Key Points: Terraces form during all sea‐level stands, and sea reoccupation is common at uplift rates ≤0.5 mm/yr; most natural terraces may be polygeneticEarthquake‐driven uplift may cause non‐preservation of individual terraces, depending on the recurrence interval ‐ coseismic uplift valuesBy keeping parameters constant and varying the model run time, terrace sequences with different morphology are created [ABSTRACT FROM AUTHOR]

Abstract Conservation soil management systems can promote beneficial changes in the edaphic fauna, which is important in improving and maintaining soil quality. Hence, this study aimed to evaluate the edaphic fauna in two areas with soils managed under no-till with and without terraces for four years. The edaphic fauna was evaluated by installing 32 pitfall trapsin each experimental plot. After seven days, the traps were removed, and the sampled individuals were classified at the level of major taxonomic groups. Collembola, Acari, Formicidae, Coleoptera, and Araneae were the most abundant in both study areas. The mean abundance of the order Coleoptera stood out in the no-till system with terraces in 2021, while the orders Collembola and Acari were more abundant without terraces in 2019 and 2021, and 2021 and 2022, respectively. There was a greater abundance of organisms for both areas in 2021, with significant equitability in the no-till system with terraces. Thus, the results showed that only some groups are positively affected by mechanical erosion control.

Most people who live in rural areas are highly dependent on shared access to natural resources including land, water, and forests for their food requirements and livelihoods. However, land degradation remains one of the biggest environmental problems worldwide. Therefore, this study proposed to develop integrated watershed management strategies for sustainable resource utilization in the Kalte River watershed. To achieve this, the SWAT model was simulated for 31 years (1992–2022), calibrated and validated at Wajifo and Humbo hydrological stations to determine the sediment and runoff from the watershed, highly sediment erosion-vulnerable part of the watershed was identified from the result of the model and the best watershed management practice was suggested for the study watershed. In total, 87,920 tons/year of sediment are yielded to Lake Abaya from the Kalte River watershed. The sediment yield was reduced by terracing at 64%, strip cropping at 59.32%, grassed waterway at 54.06%, and contour planting at 47.93%. Therefore, the highest efficiency management method in the Kalte River watershed is terracing. The watershed managers and scientific community are beneficiaries of the output of this study. Watershed managers and decision-makers can make use of the information to help them choose appropriate watershed management strategies and ensure sustainable watershed management. HIGHLIGHTS The Kalte River watershed was simulated for 31 years including a 3-year warm-up period.; The simulated model was calibrated and validated.; Erosion hotspot area was selected based on sediment yield.; Four watershed management practices are evaluated.;

Human‐created terraces are distributed extensively in the Chinese Loess Plateau, which play key roles in soil conservation, agricultural production and sustainable development. However, large‐scale and long‐term terrace mapping remains a big challenge due to the complexity of topography, land cover and the deficiency of high‐quality historical spatial data. Facing this task, our study aims to develop a new approach for capturing 30 years (from 1990 to 2020) of terrace patterns at macroscales (the whole Loess Plateau, with an area of 6.4 × 105 km2). The decision tree model (DTM) was integrated with digital elevation model (DEM) and land use data to detect terrace change, and terraced samples were extracted from existing findings for spatial validation. Our study confirmed that this new approach can work successfully on identifying cultivated and grassy terraces, as evidenced by receiver operating characteristic (ROC) curves and area under curve (AUC) values. More notably, a decreasing trend was detected in cultivated terraces with continued uneven distribution from 1990 to 2020, while the areas of grassy terraces increased markedly with more‐concentrated larger patches. This finding indicated that huge areas of terrace abandonment may have already occurred in this region. More attention thus should be paid to the rising risks of cropland utilization and food security. Since it is the first time to get long‐term reliable terrace maps on the Loess Plateau, our efforts can help to better take stock of terrace resources for wiser land use managements and agricultural policy adjustments, finally benefiting socio‐ecological sustainability. [ABSTRACT FROM AUTHOR]

Pre-Columbian food production in the Maya Lowlands was long characterized as reliant on extensive, slash-and-burn agriculture as the sole cultivation system possible in the region, given environmental limitations, with maize as the dominant crop. While aspects of this "swidden thesis" of Maya agriculture have been chipped away in recent years, there has been an underappreciation of the many forms of long-term capital investments in agriculture made by ancient Maya people. Here, we review the last three decades of research that has overturned the swidden thesis, focusing on long-term strategies. We demonstrate long-lasting agricultural investments by Maya people, in social capital including multigenerational land tenure, in cultivated capital including long-lived trees, and in landesque capital including soil amendments and landscape engineering projects, such as terracing and wetland modification. [ABSTRACT FROM AUTHOR]

Cultivated terraces are phenomena that have been protected in some areas for both their cultural heritage and food production purposes. Some terraced areas are disappearing but could be revitalised. To this end, recognition techniques need to be developed and terrace registers need to be established. The goal of this study was to recognise terraces using deep learning based on Lidar DEM. Lidar data is a valuable resource in countries with overgrown terraces. The U-net model training was conducted using data from the Slovenian terraces register for southwestern Slovenia and was subsequently applied to the entire country. We then analysed the agreement between the terraces register and the terraces recognised by deep learning. The overall accuracy of the model was 85%; however, the kappa index was only 0.22. The success rate was higher in some regions. Our results achieved lower accuracy compared to studies from China, where similar techniques were used but which incorporated satellite imagery, DEM, as well as land use data. This study was the first attempt at deep learning terrace recognition based solely on high-resolution DEM, highlighting examples of false terrace recognition that may be related to natural or other artificial terrace-like features. [ABSTRACT FROM AUTHOR]

UAV photogrammetry is a crucial technique for conserving cultural heritage sites, particularly oblique images. However, studies on this method are limited. The Jewish Neighbourhood in Akre, with its significant historical and architectural value, needs urgent documentation to prevent further deformation. This article aims to present the methods and techniques of data acquisition and processing to document the traditional terrace form of the Jewish Neighbourhood. UAV was used to capture 337 images at an altitude of 40 meters with a tilted camera angle of 45 degrees. Agisoft Metashape photogrammetry software was used to process the images and produce a 3D digital surface model of the buildings, quantitative and qualitative methods were carried out to assess the accuracy of the deliverables. In addition, Global Mapper and ArcGIS software were used to drive more documentation details that would serve to set the required operational guidelines to preserve the traditional terrace form of this site. Results show that the accuracy of the produced 3D model is high and further proves that UAV photogrammetry using oblique images is an effective technique for documenting such complex historical sites. [ABSTRACT FROM AUTHOR]

Many post-orogenic settings exhibit a rugged topography, but the underlying mechanisms driving topographic rejuvenation are poorly understood. For example, the U.S. southern Colorado Front Range, a widely recognized and studied post-orogenic setting, contains deep canyons and steep channels even though the crustal deformation that built the range during the Laramide Orogeny ended at ca. 40 Ma. Two prevailing hypotheses are typically used to explain these topographically youthful features in the Colorado Front Range: (1) mantle dynamics and active tectonics during the late Cenozoic; and (2) enhanced erosional efficiency associated with Quaternary climatic changes. Here, we evaluate these end-member hypotheses through a tectonic geomorphological study of the upper Arkansas River Basin in southern Colorado. We perform river profile analysis on bedrock channels in the eastern Rockies and map and analyze fluvial terraces in the western High Plains. In the eastern Rockies, river knickpoints record a one- to two-stage increase in base-level fall rate downstream of the Colorado Front Range mountain front and an eastward increase in the magnitude of incision. In the western High Plains, Quaternary fluvial terraces also show an eastward increase in the total magnitude of incision. Supported by flexural and supplemental geomorphic analyses, these results suggest a previously undetected regional-scale, westdirected back-tilting associated with differential rock uplift. Based on the average timing of deformation, locations of major faults, and seismic activity, seismic tomographic data, and existing geodynamic models, we infer that this newly recorded westward tilting in the upper Arkansas Basin is the result of unsteady and potentially migrating dynamic topography that developed ca. 4 Ma. [ABSTRACT FROM AUTHOR]

To extract terraced fields in hilly areas on a large scale in an automated and high-precision manner, this paper proposes a terrace extraction method that combines the Digital Elevation Model (DEM), Sentinel-2 imagery, and the improved U-Net semantic segmentation model. The U-Net model is modified by introducing Attention Gate modules into its decoding modules to suppress the interference of redundant features and adding Dropout and Batch Normalization layers to improve training speed, robustness, and fitting ability. In addition, the DEM band is combined with the red, green, and blue bands of the remote sensing images to make full use of terrain information. The experimental results show that the Precision, Recall, F1 score, and Mean Intersection over Union of the proposed method for terrace extraction are improved to other mainstream advanced methods, and the internal information of the terraces extracted is more complete, with fewer false positive and false negative results. [ABSTRACT FROM AUTHOR]

Theme parks have been described by scholars as asocial and placeless, but recent research by McCarthy demonstrated that Southern Californians exhibit a strong sense of placement attachment and sociality at Disneyland. With the third highest attendance among theme parks in Europe, De Efteling in the Netherlands provides a congruent comparison to Disneyland since both parks were based in large measure on fairy tales, opened in the 1950s near two large metropolises, and mainly designed under the creative vision of one person. This study uses mixed methods of in-depth interviews, an online survey, and participant observation to determine the sense of place attachment within cognitive, affective, and behavioral dimensions for De Efteling by local fans and then compares the results with Disneyland. The findings indicate De Efteling fans exhibit place attachment across the three dimensions largely in alignment with McCarthy's study on Disneyland, but also reveal key differences due to the nature and characteristics of the ownerships, theming, fans, and scales of operation of the two parks. This study not only further rebuts the long-held contention of theme parks as placeless and lacking sociality, but also calls for exploration and comparison with other global theme parks. [ABSTRACT FROM AUTHOR]

Vegetated terraces are becoming increasingly widespread, given their benefits in terms of regulating the building's climate and the speed of rainwater run-off. The first step in this research was to select plantations that can withstand the conditions of terraces. This involves selecting low-maintenance plants, substrates and aggregates for mineralised terraces that do not require maintenance. You'll need to take into account the local climate, the thickness of the substrate you can lay on the terrace. Terraces require the use of perennial plants, which are resistant to temperature differences and grow fairly quickly. This allows the roof surface to be covered quickly, and also protects the building from extremes of temperature, high in summer and cold in winter. Tests were carried out to compare the effects of different terrace coverings on the temperature inside the building in different seasons. The results obtained show that the 10 cm thick layer of roofing has a warming effect during the cold period (0.84°C) and a cooling effect during the warm period (0.32°C), and that the 5 cm thick layer of terrace roofing has a cooling effect during the warm period (0.64°C) and a warming effect during the cold period (1.32°C). [ABSTRACT FROM AUTHOR]

During a butterfly survey in the remote village of Gailung in Chamoli district, Uttarakhand, one Common Tinsel was recorded on 27th March 2023. The butterfly was photographed and identified with the help of field guides as Catapaecilma major Druce, 1895 (Lepidoptera, Lycaenidae). The habitat was adjacent to local terrace farmland and was dominated by plants such as Ageratum conyzoides, Oxalis sp., Urtica sp., Fluggea virosa, and Bauhinia variegata. The butterfly was observed resting on the leaves of Ageratina adenophora. and was noted for its swift flight. The current communication highlights the first observation of Common Tinsel from the Garhwal Himalaya after 1930s. [ABSTRACT FROM AUTHOR]

Rice terraces are crucial for agriculture in China's southern mountainous regions. Land use and land cover change (LUCC) in these areas impact hydrology, but our understanding is limited. In this study, we applied the hydrological assessment tool SWAT to a selected small watershed in the rice terrace-dense area of central Hunan province, China. This study covered four LUCC periods over the past 40 years and was simulated at annual and monthly scales. The results showed that from 1980 to 2020, the areas of paddy fields and drylands decreased by 4.19% and 5.76%, respectively, while the areas of forests and construction land increased by 1.14% and 92.48%, respectively. During the past period, LUCC led to a decrease of 1.77% and 2.49% in runoff and infiltration, respectively, and an increase of 1.03% in ET. However, the water yield remained almost unchanged, indicating that the rice terrace plays a positive role in maintaining stable watershed water yield under LUCC. The results of the sub-basin analysis indicated that the transformation of paddy fields and forests directly determines the trend of hydrological changes. Land use type had the most significant impact on the runoff of the rice-terrace watershed, with the proportions of paddy fields and forests being the most influential factors. Paddy fields significantly influenced the stability of runoff at the watershed scale, suggesting that a high paddy field ratio doesn't ensure sustainability. This study offers valuable insights for managing small watershed terraces, land use planning, and achieving sustainable development in the watershed. [ABSTRACT FROM AUTHOR]

Sloping farmland abandonment has become a typical land use pattern worldwide. Along with the aggravation of sloping farmland abandonment, terrace abandonment is also showing an increasing trend. Systematically clarifying the pattern and mechanism of terrace abandonment is a prerequisite for effective management. Based on the survey data of 145 villages, 697 rural households, and satellite remote sensing in Southwest China, this study uses spatial analysis and the Logit model to reveal the scale, pattern, and driving mechanism of terrace abandonment in the study area to provide scientific references for the sustainable utilization of terrace resources in mountainous areas. This study found that in the study area, 63% of the villages had experienced terrace abandonment, and nearly one-fifth of the rural households had abandoned terraces. The area of abandoned terraces accounted for 7.65% of the total area, and the scale of abandoned terraces reached 449,360 hectares, of which Chongqing has the highest proportion of terrace abandonment (11.5%), while Yunnan Province has the lowest (5.1%); the overall abandoned terraces show a pattern of higher in the east and lower in the west. Terrace abandonment is influenced by multiple factors. The rise in non-agricultural wages attracts rural labor migration as an external force, while the rising operating costs of mountain agriculture serve as internal drivers. Under the combined influence of internal and external factors, the abandonment of terraces in southwest mountainous areas is intensifying. The government should actively conduct assessments of terrace resources within the region and implement targeted measures to address terrace abandonment. [ABSTRACT FROM AUTHOR]

A field experiment was conducted in the Zhangjiachong watershed to analyze the characteristics of rainfall–runoff process and sediment yield under different types of terraces. Various runoff plots were utilized, and a two serial tank model was employed to simulate runoff generation and concentration processes, taking into account vegetation interception. A soil erosion model incorporating raindrop erosion and sheet erosion was established to replicate sediment yield and concentration process. The parameters of the rainfall–runoff model and soil erosion model were calibrated and validated using observed runoff and sediment yield data. The controlling factors on runoff and sediment yield were explored and compared. The results indicate that both calibration and validation outcomes were acceptable. The earth‐banked terraces–citrus demonstrated the largest coefficients of upper and lower surface runoff, while its upper runoff threshold of the upper tank and the runoff threshold of the lower tank were the lowest, suggesting that it was more likely to produce surface and subsurface runoff. On the other hand, the stone dike terraces–crops exhibited the smallest coefficients of upper and lower surface runoff, while its upper runoff threshold of the upper tank was the highest. The lower runoff threshold of the upper tank was the same across different types of terraces. Compared to the earth‐banked terraces, the stone dike terraces have a larger infiltration coefficient in the upper tank and a smaller infiltration coefficient in the lower tank. Sensitivity analysis indicates that the most sensitive factors affecting runoff simulation results are the runoff threshold and the infiltration coefficient of the lower tank. Terraces, whether constructed with earth banks or stone dikes, are effective in reducing soil erosion. However, during storm rainfall events, these terraces may be partially destroyed, resulting in a higher sediment yield than that of the same vegetation cover on slope land. Terraces with hedgerows have a more significant effect on reducing runoff and sediment than those without hedgerows. [ABSTRACT FROM AUTHOR]

Through field investigation in the Zoige Basin of the eastern Tibetan Plateau, a natural and complete sedimentary profile was found on the steep cliff of the first terrace of the right bank of the Yellow River in the Maqu reach. Careful field observation, analysis of particle size characteristics, and optically stimulated luminescence dating were conducted. The results showed that the paleo-riverbed pebble layer and the floodplain sandy silt layer at the bottom of the sedimentary profile constituted a typical binary sedimentary structure layer, in which the shallow depression bog mud layer that formed during 5.0–4.2 ka was lenticularly sandwiched in the floodplain sandy silt layer, indicating that the first terrace of the Yellow River in this reach began to form at 5.0 ka. The climate was dry and cold during 4.2–4.0 ka, and strong wind on the plateau surface transformed the floodplain sediments into aeolian sand. The paleoflood slackwater deposits sandwiched in the aeolian sand layer indicated that the source of the Yellow River has experienced several catastrophic flood events during this period, inundating the first terrace ground. During 4.0–2.8 ka, mud bogs formed in shallow depressions of the terrace under the relatively humid climate. After 2.8 ka, sandstorms drove the accumulation of coarse silt over the terrace ground, forming aeolian loess. The upper part developed into modern subalpine meadow black soil with granular structure through biological weathering since 2.0 ka. The study results revealed the formation age and its surface development process of the first terrace of the Yellow River in the Zoige Basin, which has important scientific significance for in-depth understanding of the water system evolution and environmental changes in the source area of the Yellow River. OSL dating and stratigraphic framework comparison with XCC profile and WDT profile (Chai et al., 2021) indicated that the first terrace began to form at 5.0 ka along the Maqu reach of the Yellow River in the western margin of the Zoige Basin, Eastern Tibetan Plateau. [Display omitted] [ABSTRACT FROM AUTHOR]

Shallow seamounts at ocean island hotspots and in other settings may record emergence histories in the form of submarine erosional terraces. Exposure histories are valuable for constraining paleo-elevations and sea levels in the absence of more traditional markers, such as drowned coral reefs. However, similar features can also be produced through primary volcanic processes, which complicate the use of terraced seamounts as an indicator of paleo-shorelines. In the western Galapagos Archipelago, we utilize newly collected bathymetry along with seafloor observations from human-occupied submersibles to document the location and depth of erosional terraces on seamounts near the islands of Santiago, Santa Cruz, Floreana, Isabela, and Fernandina. We directly observed erosional features on 22 seamounts with terraces. We use these observations and bathymetric analysis to develop a framework to identify terrace-like morphologic features and classify them as either erosional or volcanic in origin. From this framework we identify 79 erosional terraces on 30 seamounts that are presently found at depths of 30 to 300 m. Although intermittent subaerial connectivity between the islands has been hypothesized, the depths of these erosional terraces in the Santiago region are the first direct evidence of paleo-connectivity in the modern archipelago. Collectively, the terraces have non-randomly distributed depths. We suggest that peaks in the distribution of terrace depths likely represent long durations of exposure (i.e., sea-level still or lowstands). By comparing these peaks to those of subsidence adjusted sea-level curves, we identify the average subsidence rate that best reproduces the observed terrace distributions. These rates are 0.2-0.4 m/ka for this portion of the central Galapagos, since the formation of the seamounts, consistent with previous independent estimates. Using these subsidence rates and evidence for erosional terraces at depths up to 300 m, we conclude that all islands in the central archipelago have been intermittently connected starting between 435 and 900 ka. Individual island pairs have likely been repeatedly subaerially connected for short intervals since that time. [ABSTRACT FROM AUTHOR]