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This paper discusses a model of coastal barrier progradation where the development of a prograded plain was a product of the successive formation of foredune ridges followed by their burial by transgressive sand sheets and dunefields. The results are based on direct lithological data from drill holes and geomorphological analyses, indirect geophysical data (GPR), and 14C and OSL dating. Barrier progradation started at 6.69 ka (OSL) or 7.2 ka (14C), under sea-level rise. At around 5.0 ka (OSL), or thereabouts, a forced regression condition started to operate, when sea-level started to fall after it reached a maximum of 2.34 ± 0.8 m. During barrier progradation sets of foredunes were formed, and at least some of them were buried by sands of transgressive dunefields (TDF), which later evolved to transgressive sand sheets (TSS). A total of 11+ phases of TSS and a modern phase of TDF were formed in a time span of 6.69 ka (OSL) or 7.2 ka (14C), corresponding to one phase formed at each 560 or 600 yrs. Two models of possible development of the surface of Curumim barrier are proposed. • Arare record of aforedune plain buried by transgressive sandsheets formation. • The cyclic formation of transgressive dunefieldsand transgressive sand sheets. • The foredune/beach contact as a proxy of sea-level position. • Distinct contributions of normal and forced regressionon barrier progradation. • Possibletransformation of a transgressive dunefield in a transgressive sand sheet. [ABSTRACT FROM AUTHOR]

This paper presents new sedimentological, geomorphological, and optically stimulated luminescence (OSL) geochronological evidence for fluvial evolution of the mid- to lower River Tyne through the Lateglacial to late Holocene. These data reveal a series of fluvial terraces produced by cycles of aggradation and incision, conditioned by glacial inheritance and driven by changing sediment availability and hydrological regime. The distribution and stratigraphy (where available) of nine river terrace and their associated sediments have been recorded. At two key sites the sediments have been dated using OSL measurements to constrain the fluvial geomorphology. Significant entrenchment of the fluvial system, followed by aggradation formed the earliest fluvial terrace (T1), which encompasses environments spanning the transition from deglaciation into Greenland Interstadial 1 (GI-1). Incision below T1 began towards the end of GI-1, with three terraces (T2 – T4) between the abandonment of T1 and the early Holocene (15.0–9.2 ka). Climatic shifts, limited vegetation cover/soil development, and peri −/paraglacial landscape instability conditioned the development of the early postglacial fluvial landsystem. Three further terraces (T5 – T7) developed during the mid- to Late Holocene (6.6–3.1 ka), and comprise most of the valley floor. Climatic instability, glacial inheritance, and widespread anthropogenic disturbances are reflected in greater hillslope-channel coupling during this period. The extent of later Holocene terraces (T8 – T9) is limited as the river became isolated from flanking hillslopes entrenched between existing river terraces. Fluvial landscape evolution in formerly glaciated catchments is strongly conditioned by the cold stage legacy that introduced excess sediment and landscape instability into the catchment. Subsequent catchment-wide responses are variable and non-linear, with valley floors operating in a series of reach-wide responses. There is a need for greater chronological control to constrain the Lateglacial and Holocene evolution in the Tyne catchment, but also to further our understanding of region-wide responses to external drivers and local dynamics. • Lateglacial to late Holocene fluvial response recorded from river terrace sequence. • Fluvial landscape strongly conditioned by glacial legacy. • Catchment-wide responses are non-linear and valley floors operated as reach-wide responses. • River responded to climate and/or landscape perturbations at ∼16, 11.9, 8.7, 4 ka. [ABSTRACT FROM AUTHOR]

The Bohai Sea is a semi-enclosed shallow shelf sea that has undergone a unique sediment source-to-sink process in the past. Despite this, our knowledge about the sediment budget, existence of depocenters and the factors controlling depocenter formation during the Holocene remains limited. This paper aims to address these gaps by estimating the Holocene marine deposit thickness and sediment budget in the Bohai Sea using high-resolution subbottom profiles. The results reveal that the mean thickness of Holocene marine deposits is approximately 7.8 m and a maximum thickness of 28 m was found in Jinzhou Bay. The Highstand System Tracts (HST) have a mean thickness of approximately 5.4 m and a maximum thickness of 25 m observed in the Jinzhou Bay. On the other hand, the Transgressive System Tracts (TST) have a mean thickness of approximately 2.5 m and a maximum thickness of 7 m in the north of the Laizhou Bay. The total accumulation in the Bohai Sea is estimated to be ∼713.97 × 109 tons, consisting of 489.28 × 109 tons from the HST and 224.69 × 109 tons from the TST. Three deposit centers were identified and estimated to be approximately 299 × 109 tons, accounting for approximately 42 % of the total Bohai Sea sediments. The development of Holocene marine deposit centers was mainly influenced by the Tanlu Fault zone and water circulations. Based on preliminary estimates, it is suggested that roughly half of the sediments dispersed from the estuaries are preserved on the Bohai Sea shelf since the maximum flooding (∼7000 cal yr BP). This research provides valuable insights for the post-glacial sedimentary and geomorphic evolution of the Bohai Sea. • Holocene marine accumulation in the Bohai Sea is estimated to be ∼713.97 × 109 tons. • Accumulation in HST is of ∼489.28 × 109 tons and that in TST is of ∼224.69 × 109 tons. • Three depocenters were identified and account for ∼42 % of the total accumulation. • Roughly half of the sediments were preserved on the shelf over the past 7000 years. [ABSTRACT FROM AUTHOR]

Abstract: Quantitative palaeoglaciological studies that use digital surface models (DSMs) may be subject to error because former glacier beds are not always accurately represented. This is because the Earth's surface may have changed significantly since deglaciation. This paper evaluates some of the potential errors caused by postglacial sedimentation, by comparing the results of physical palaeoglaciological reconstructions and bedform morphometric analyses in parts of Scotland, using both the modern land surface and interpolated former glacier beds derived from borehole data. For a former terrestrial outlet glacier, removal of postglacial sediments increases the modelled ice surface elevation and ice thickness by 0.7% and 5%, respectively, over a 27-km flow line. For a former tidewater glacier, the reconstructed steady state ice flux is increased by 250% when the modern land/seabed surface is replaced with an interpolated former glacier bed. In a classical drumlinised landscape, removal of postglacial sediments affects bedform morphometrics, with an increase in measured drumlin length, width, relief, and volume. The cases presented in this paper are from environments known to have experienced postglacial sedimentation. They provide situational examples of the degree of error that can be introduced when the modern land surface is used to represent former glacier beds in these environments. In some regions, sufficient subsurface data exists over large areas to create improved topographic representations of former glacier beds; these could form important inputs to the next generation of palaeo-ice-sheet and palaeo-glacier simulations. [Copyright &y& Elsevier]

The last decade increasing evidence of soil erosion by sediment run-off predating agriculture has been found in different areas of west and central Europe. A central discussion is whether pre-agricultural erosion was triggered by vegetational disturbances caused by hunter-gatherer activities (trampling, controlled forest fires) or natural processes (e.g. climatic anomalies, wildfires, wind-throws). This paper contributes to this discussion using data recently gathered during archaeological excavations of a levee, within the floodplain of the River Scheldt in NW Belgium, occupied by hunter-gatherers during the Early Holocene. These excavations revealed the presence of a ca. 40 cm thick slope deposit, which was radiocarbon dated to the late Preboreal and 1st half of the Boreal. A high-resolution, multi-proxy analysis of this deposit demonstrates a close correlation between the type of vegetation, forest fires and erosion intensity. It is concluded that repeated burning of pine-dominated forests was most likely the main trigger. Furthermore, this study provides strong evidence against an anthropogenic origin of these Early Holocene fires as burning and slope erosion already started long before prehistoric hunter-gatherers occupied the levee top and the Scheldt basin. Furthermore, this study demonstrates that pre-agricultural slope erosion was not limited to hilly regions with pronounced topography but also occurred in lowland regions with subtle topographical gradients. • This study confirms pre-agricultural slope erosion dating back to the Early Holocene. • It demonstrates its occurrence in lowland environments with subtle topographical gradients. • Erosion is linked to repeated surface fires of pine-dominated forests. • The role of prehistoric man and climate is estimated to be limited. [ABSTRACT FROM AUTHOR]

This paper reports the first reconstruction of storm-generated late Holocene and historical river floods in the North Island of New Zealand. The sedimentary infills of nine palaeochannels were studied in the lower alluvial reaches of the Manawatu River. Floods in these palaeochannels were recorded as a series of sand-rich units set within finer-grained fills. Flood chronologies were constrained using a combination of radiocarbon dating, documentary sources, geochemical markers, and palynological information. Flood units were sedimentologically and geochemically characterised using high resolution ITRAX™ X-Ray Fluorescence (XRF) core scanning and laser diffraction grain-size analysis. The longest palaeoflood record extends back ca.3000 years. The temporal resolution and length of the Manawatu record reflects accommodation space for fluvial deposits, channel dynamics and mobility, and high sediment supply. Floods that occurred in the Manawatu during the mid-1800s at the time of European land clearance and in the first decade of the twentieth century appear to be among the largest recorded in the last 3000 years. [ABSTRACT FROM AUTHOR]

The geomorphological development of Holocene coastal plains around the world has been studied since the beginning of the twentieth century from various disciplines, resulting in large amounts of data. However, the overwhelming quantities and heterogeneous nature of this data have caused the divided knowledge to remain inconsistent and fragmented. To keep improving the understanding of coastal plain geomorphology and geology, cataloguing of data and integration of knowledge are essential. In this paper we present a GIS that incorporates the accumulated data of the Netherlands' coastal plain and functions as a storage and integration tool for coastal plain mapped data. The GIS stores redigitised architectural elements (beach barriers, tidal channels, intertidal flats, supratidal flats, and coastal fresh water peat) from earlier mappings in separate map layers. A coupled catalogue-style database stores the dating information of these elements, besides references to source studies and annotations regarding changed insights. Using scripts, the system automatically establishes palaeogeographical maps for any chosen moment, combining the above mapping and dating information. In our approach, we strip the information to architectural element level, and we separate mapping from dating information, serving the automatic generation of time slice maps. It enables a workflow in which the maker can iteratively regenerate maps, which speeds up fine-tuning and thus the quality of palaeogeographical reconstruction. The GIS currently covers the late Holocene coastal plain development of the Netherlands. This period witnessed widespread renewed flooding along the southern North Sea coast, coinciding with large-scale reclamation and human occupation. Our GIS method is generic and can be expanded and adapted to allow faster integrated processing of growing amounts of data for many coastal areas and other large urbanising lowlands around the world. It allows maintaining actual data overview and facilitates new ways of analysis at national, regional, and local scales. [ABSTRACT FROM AUTHOR]

James C. Knox was best-known for his work on Holocene and historical changes in fluvial systems, but he also had a long-standing interest in the effects of late Pleistocene periglacial environments on landscape evolution in parts of the Upper Mississippi River basin that were just outside the Laurentide Ice Sheet margin, or as Knox put it, ‘up in the refrigerator.’ Knox and others in the Quaternary community of the Midwestern U.S. often suggested that hillslope erosion was accelerated under periglacial conditions, so that glacial periods have had a dominant effect on the landscape we see today. This paper reviews the evidence and reasoning supporting that view in a study area of the Upper Mississippi basin bordered on three sides by ice margins of the last glaciation, including the Wisconsin Driftless Area and adjacent landscapes. Sparse but compelling paleoecological data and relict ice- or sand-wedge polygons provide clear evidence for a cold climate and widespread permafrost around the peak of the last glaciation. In highly dissected, relatively high-relief parts of the study area, the loess and soil stratigraphy on ridgetops and the colluvial mantles on steeper slopes are best explained by highly effective hillslope erosion, including solifluction, during and just after the Last Glacial Maximum. Knox used the post-depositional truncation of a loess unit to quantify contrasting late Pleistocene and Holocene sediment yields from a small Driftless Area watershed. While the late Pleistocene yield indicates accelerated erosion, it is still lower than modern sediment yields in many tectonically active or semiarid landscapes, and it may reflect deposition of highly erodible loess as well as effects of periglacial conditions. The views of Knox and other Midwestern geomorphologists on landscape evolution through glacial–interglacial cycles were highly influenced by the work of Robert V. Ruhe. Ruhe proposed that an episode of widespread erosion during and just after the Last Glacial Maximum can explain enigmatic aspects of Quaternary stratigraphy and the soil landscape on the Iowan Erosion Surface, a very low relief landscape of the study area. Ruhe's key evidence is still valid, though it needs to be separated from an implausible model of landscape evolution. Interpretation of the Iowan Erosion Surface and other low-relief landscapes just outside the ice margin also requires recognition of the profound effect of eolian processes on those landscapes under periglacial conditions. Many new insights on landscape evolution in the study area could result from wider application of cosmogenic nuclide-based methods to assess glacial–interglacial changes in basinwide rates of erosion and residence time of soils. Just as important, a need exists for much more field-based characterization of hillslope, fluvial, and eolian sediments for comparison with those of modern permafrost regions and past periglacial environments in Europe. [ABSTRACT FROM AUTHOR]

This paper presents a new and simple recursion model to calculate the erosion rates of flights of narrow, late Holocene terraces under conditions of regular uplift. The general equations developed are: Δ x n = Δ x ′ n + Δ x n − 1 − Δ z n − 1 / tan θ n − 1 , and ε n = Δ x n / ( t n − t n + 1 ), where n is the number of narrow terraces, Δ x n is the original width of narrow terrace n , Δ x ′ n is the observed width of narrow terrace n , Δ x n − 1 is the original width of narrow terrace n – 1 (one step below terrace n ), Δ z is the height of the narrow terrace, θ is the gradient of the slope, and ε is the backwearing (i.e., horizontal erosion) rate. The model can be used to calculate the backwearing rate if the widths of the present shore platform and of the emerged narrow terraces can be obtained, and where chronological control is available. Backwearing rates on the Ashizuri, Boso and Kii peninsulas in Japan were calculated using the model to be approximately 0.001, 0.2–1.0, and 0.009 m/yr, respectively. These calculated values are in agreement with the rates of backwearing directly measured in previous studies. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to describe the late Holocene behaviour of rivers using an interdisciplinary approach combining fluvial geomorphology and subfossil trunk dendrochronology. The subfossil wood material collected along the rivers was investigated for dendrometric and dendrochronologic parameters. The research methods in these fields helped us to understand the effect of the fluvial environment on riparian trees and their records and helped in reconstructing the riparian palaeoenvironment. The study area consists of two rivers with different typologies but comparable sizes: the Moldova River, which features a braided to wandering channel in its lower reach, and the Siret River, which features a sinuous-meandering channel. Along the 100-km-long floodplain of the former and the 144-km-long floodplain of the latter, we found and sampled 77 subfossil trunks, of which 26 were subjected to 14 C dating. The resulting data consist of floodplain facies mapping data, electric resistivity measurements, absolute dates, and dendrometric and dendrochronologic data. The results indicate that during a 100-year period, the two rivers were sensitive to climate change and anthropogenic effects, particularly a narrowing of the active channel by 76% in the braided channel and 38% in the sinuous-meandering channel. During the past 3300–3000 YBP, the Moldova River maintained its braided style, whereas the sinuous-meandering style has been characteristic of the Siret River for the previous 6800–4600 YBP. The two distinct fluvial environments are recorded in the dendrometric structure of the trunks buried in the channel-fill sediments. The braided fluvial environment was more effective in uprooting riparian trees and incorporating them in the floodplain deposits, whereas the sinuous-meandering style of stream effectively buried tree trunks in lateral accretion lobes. Absolute and dendrochronologic dating allowed for the reconstruction of timelines of the felling of the trees and estimates of the magnitude of the responsible hydrological event. The flood events on the Siret River with a recurrence interval of 200 years ( Q max ~ 2500–2800 m 3 /s) were those most effective in destroying riparian forests, and the events on the Moldova floods with a 100-year recurrence interval ( Q max ~ 1200–1400 m 3 /s) were the most effective. Dendrochronology allowed for identification of wet phases (i.e., 3500–2900 YBP, 2200–2075 YBP, and 1000–800 YBP) and dry phases (e.g., 3200–3150 or 2775–2700 YBP, 1400 YBP). Finally, we draw attention to the potential for creating a highly replicable dendrochronological series spanning at least 7000 YBP. [ABSTRACT FROM AUTHOR]

Marine tidal notches are developed by bioerosion in the intertidal zones of rocky coasts, but a combination of sea-level change and crustal movements can result in them being raised above or submerged below the water line. For that reason, the present-day elevation of these former shorelines relative to the mean sea level has long been used to quantify relative coastal uplift and subsidence in tectonically active areas, assuming that the sea-level (eustatic) change component is known. Along the microtidal Mediterranean littoral, it is generally assumed that notches develop during relative stillstands of sea level, when tectonic and eustatic trends are in unison, and that discrete notch levels record abrupt shoreline changes caused by local seismic displacements. Recently, however, a climatic model for notch formation has been proposed, in which stable periods of Holocene climate favour enhanced erosion; in this competing model, the rate of sea-level rise is lower than the tectonic uplift rate and individual notches are not specific seismic indicators. Because marine notches are widely used as geomorphic markers of tectonic, and in some cases palaeoseismic, movements, a reappraisal of the geological significance of these strandlines is warranted. In this paper, we explore the two conflicting notch models using a database of Eastern Mediterranean palaeoshorelines. Although we conclude that the spatial and temporal distribution of the notches supports a dominantly tectonic control on notch genesis as a result of earthquake clustering, we highlight how the diachronous timing of notch development tempers their value as tectonic markers. [ABSTRACT FROM AUTHOR]

It is widely accepted that climate has a strong impact and exerts important feedbacks on erosional processes and sediment transport mechanisms. However, the extent at which climate influences erosion is still a matter of debate. In this paper we test whether frost-cracking processes and related temperature variations can influence the sediment production and surface erosion in a small catchment situated in the eastern Italian Alps. To this extent, we first present a geomorphic map of the region that we complement with published 10 Be-based denudation rates. We then apply a preexisting heat-flow model in order to analyze the variations of the frost-cracking intensity (FCI) in the study area, which could have controlled the sediment production in the basin. Finally, we compare the model results with the pattern of denudation rates and Quaternary deposits in the geomorphic map. The model results, combined with field observations, mapping, and quantitative geomorphic analyses, reveal that frost-cracking processes have had a primary role in the production of sediment where the intensity of sediment supply has been dictated and limited by the combined effect of temperature variations and conditions of bedrock preservation. These results highlight the importance of a yet poorly understood process for the production of sediment in mountain areas. [ABSTRACT FROM AUTHOR]

This paper focuses on simulations of the morphological evolution of an estuary during sedimentary infilling that accompanied Holocene sea-level rise. The simulations were conducted using the Estuarine Sedimentation Model, which uses a behaviour-oriented approach, supported by the chronostratigraphy of the estuary's sedimentary sequence. Behaviour curves were computed to represent the relationship between the estuarine channel depth below maximum high tide and the net accretion at a given location relative to the average sedimentation rate of the estuary during the Holocene. The model was validated by comparing the observed present-day bathymetry of the Guadiana River Estuary, southeastern Portugal, with the corresponding simulated bathymetries for nine control sections across the estuary. The best fit between simulated and actual sediment surface elevations was obtained along the cross-sections in the sheltered, low-energy environments of the estuary. The accuracy of the sedimentary stratigraphy of the best-fit model was further established using 16 radiocarbon ages obtained from five boreholes in the estuary. The present approach is particularly suitable for simulating long-term morphological evolution in sheltered estuarine environments where tidally driven vertical aggradation dominates at centennial to millennium timescales. However, the accuracy of simulated sediment surface elevations and consequently the robustness of behaviour-type models based on Geographical Information System platforms can be enhanced by incorporating (i) the impacts of nearshore hydrodynamic processes and episodic flood events in highly energetic channels, and (ii) the impacts of cross-currents in meandering channel sections. [ABSTRACT FROM AUTHOR]

The presence of a regional-wide notch (45 to 115cm below present biological mean sea level [BMSL]) along the Adriatic coast of Croatia, at a string of sites between Zadar and Rijeka, provides evidence for a rapid but poorly constrained subsidence event(s) after Roman times. For more than a century, this geomorphological tidal level indicator has attracted rich scientific debate but many unresolved questions remain. In this paper, we present new results from Caska Bay (Pag Island) looking at notch morphology and Holocene salt-marsh stratigraphy to constrain the chronology of this crustal deformation on Pag Island. The typical salt-marsh stratigraphy comprises low to high salt-marsh muds interjected by an unconformable marine layer (which lies between -50 and -100cm BMSL) consistent with an abrupt transgression. The palaeoecological record shows an abrupt shift in assemblages across the salt-marsh mud-sand sediment contact translating abrupt coastal changes. Geochronological data constrain this event to around 1000 to 1200cal. AD. The altitude of the layer is coeval with the submerged notch attested on limestone cliffs around the bay. The U-shape of the notch profile, coupled with the sharp palaecological contacts and submerged Roman pier, implies that sea-level rise was episodic and not gradual as suggested by regional numerical models. Together, our findings shed new light on the chronology of the "enigmatic" Croatian notch on the island of Pag, and highlight the need to couple geomorphological studies of rocky coasts with high-resolution sediment records. [ABSTRACT FROM AUTHOR]

Abstract: Few studies have aimed to reconstruct landscape change in the area of Eretria (South Central Euboea, Greece) during the last 6000years. The aim of this paper is to partially fill in this gap by examining the interaction between Mid- to Late Holocene shoreline evolution and human occupation, which is documented in the area from the Late Neolithic to the Late Roman period (with discontinuities). Evidence of shoreline displacements is derived from the study of five boreholes (maximum depth of 5.25m below the surface) drilled in the lowlands of Eretria. Based on sedimentological analyses and micro/macrofaunal identifications, different facies have been identified in the cores and which reveal typical features of deltaic progradation with marine, lagoonal, fluvio-deltaic and fluvial environments. In addition, a chronostratigraphy has been obtained based on 20 AMS 14C radiocarbon dates performed on samples of plant remains and marine/lagoonal shells found in situ. The main sequences of landscape reconstruction in the plain of Eretria can be summarized as follows: a marine environment predominated from ca. 4000 to 3200cal.BC and a gradual transition to shallow marine conditions is observed ca. 3200–3000cal.BC due to the general context of deltaic progradation west of the ancient city. Subsequently, from ca. 3000 to 2000cal.BC, a lagoon occupied the area in the vicinity of the Temple of Apollo and the settlement's development was restricted to several fluvio-deltaic levees, thus severely limiting human activities in the plain. From ca. 2000 to 800cal.BC, a phase of shallow marine presence prevailed and constrained settlement on higher ground, forcing abandonment of the major part of the plain. Finally, since the eighth century BC, the sea has regressed southward and created the modern landscape. [Copyright &y& Elsevier]

Abstract: The Metaponto Coastal Plain (MCP), in southern Italy, stretches 60km-long and 5km-wide along the Gulf of Taranto in the Ionian Sea, and is presently subject to strong anthropogenic pressure. A multidisciplinary study reviewed the geomorphology, lithostratigraphy and sedimentology of the MCP and its subsurface. Incorporating both borehole and radiocarbon-dating information in the review, this paper focuses on comparisons and differences between present-day and buried Late Pleistocene landscapes (LGM and MIS 3). The modern coastal plain is the top of a late Holocene coastal wedge prograding on a very narrow-shelf, that is connected to a deep basin (the Ionian Sea) by a steep slope. This scenery likely resembles those produced during earlier late Quaternary relative highstands and is in marked contrast with that produced during the last sea-level fall and lowstand, and buried in the MCP subsurface. The last scenery corresponds to the LGM landscape, where river-valleys deeply dissected a previous highstand coastal wedge (MIS 3) whose remnants represented interfluve areas. Thanks to resonance properties of the subsurface, this buried landscape was obtained in a 3D visualization, highlighting location and shape of incised valleys and interfluve areas during the LGM. [Copyright &y& Elsevier]

Abstract: This paper reviews the sedimentological and geomorphological imprints of prehistoric and historical tsunamis in the four main estuaries of SW Spain. These imprints include beach erosion, filling of intertidal channels, deposition of bioclastic layers, washover fans and reworked aeolian sheets and the breaching of spits and tombolos. Most of these imprints were caused by the 218–209BC and AD1755 tsunamis, although evidence of other tsunamis has been identified. In these two events, effects on human populations were severe and diverse, such as human loss of life, changes in coastal settlements and international borders, damage to port infrastructure or flooding of marsh and inhabited areas. New radiocarbon reservoir data were included in order to obtain an approach to the recurrence period of these high-energy events (700–1000years) in this area. [Copyright &y& Elsevier]

This paper discusses Howard et al. (2012) who reconstruct the peak discharge of a glacial outburst flood, or ‘jökulhlaup’, for part of the Jökulsá á Fjöllum in north-central Iceland. They propose that this flood was the largest on Earth. We consider that the magnitude of the jökulhlaup proposed by Howard et al. (2012) warrants much more robust field evidence and demands more carefully parameterised hydraulic modelling. For these reasons we firstly (i) present their study in the context of previous research (ii) highlight issues with attributing landforms and sediments to jökulhlaups, and (iii) consider uncertainty regarding the timing and magnitude of jökulhlaups along the Jökulsá á Fjöllum. We argue herein that whilst a range of landforms and sediments that are attributable to jökulhlaups can be observed along the Jökulsá á Fjöllum, these are not necessarily diagnostic of jökulhlaups. Secondly, we critically discuss (iv) the major underlying assumptions of their study, and (v) their calculations and subsequent interpretations. These assessments lead us to consider that the proposal by Howard et al. (2012) of the largest flood on Earth is highly unrealistic, especially when due consideration is given to a possible source area and a trigger mechanism. [ABSTRACT FROM AUTHOR]

Abstract: In humid climate zones, like Central Europe, past soil erosion and gullying are strongly connected with agricultural expansion, and extreme soil erosion events often play an important role in land abandonment. This paper provides a case study to demonstrate the interaction between land use, soil erosion, floodplain development, and land use changes in a 0-order catchment in the Babikovce catchment, Myjava Hill Land, situated in western Slovakia. Sedimentological, pedological, geoarchaeological and historical data indicate two main periods of intensive hillslope erosion and gullying since the High Middle Ages. In particular, a few extreme precipitation events (or rapid snowmelts) caused intensive runoff events and gullying on cleared land. The formation of the gully system and fan deposits in the Babikovce catchment and other areas also forced the occurrence of intensive muddy floods and caused floodplain aggradation and meander changes along rivers in the Myjava Hill Land. As a result, the development of the dense network of permanent gullies in the Myjava Hill Land can be associated with the transformation of woodland into farmland and later land abandonment. Today, the area is highly truncated by soil erosion and very difficult to farm. [Copyright &y& Elsevier]

Abstract: The Kamienne Mts. in SW Poland abound in geomorphic evidence for past landslides developed at the rhyolite/sedimentary rock contact, but it remains unknown when the displacements occurred. The slopes generally have been stable in the last 200years or so, covered by historical records. In this paper we use the presence of periglacial solifluction layers (cover-beds) and soil characteristics as indicators of the status of hillslopes and relative age of landslides. We follow an assumption that if landslides predate the Holocene, then solifluction layers should be present and soils within and outside landslide-affected slopes should have similar characteristics, allowing for differences caused by local factors. Cover-beds are not expected to be associated with Holocene landslides. Differences in the degree of soil development may be used to argue for different ages of some landslides within the Holocene. The absence of solifluction layers cannot always be regarded as the evidence of post-Pleistocene landsliding since such a layer is unlikely to have ever formed on densely jointed, but otherwise strong, rhyolite. Soil morphological properties, particularly horizonation, helped to establish the relative chronology of mass movement and to recognize both early to mid-Holocene and late Holocene landslides. Soils are good relative-dating tools and their usage does not necessarily require adherence to any particular soil classification system. This is because morphological features of entire profiles provide more information than diagnostic properties used in these systems. [Copyright &y& Elsevier]

Abstract: Landscape evolution in active mountain chains can be dominated by gravitational slope movements. This is observed in a large portion of the Reno river catchment, Apennines, Italy, where weak rocks, such as clayshales, are subject to earthflows that control hillslope morphology and supply sediments to the channel network. In this paper, we evaluate the sediment flux generated by earthflows and compare it with Holocene-averaged deposition rates to assess the contribution of mass movements to landscape evolution. Present-day hillslope sediment flux is estimated by combining measured displacement rates (72 inclinometers) and spatial attributes of earthflows and historical frequency of reactivations. Averaged sediment yield (~1.6x103 t/km2/yr) compares well with similar studies on earthflow-dominated landscapes, despite notable differences in methodology. In the study area, the connectivity between hillslopes and the stream network is well developed and no significant sediment sinks influence the sediment transport processes. We document best estimates of regional sediment fluxes and related uncertainties, based on available data. Coarse limestone fragments, present in the clayshales, are used as a natural sediment tracer to allow a comparison with sedimentation rates taking place at the mouth of the intramontane catchment. Here, available borehole logs, 14C datings and stratigraphic correlations of the alluvial fan are used to obtain an estimate of the deposition that took place during Holocene times. Taking also into account the role of solute transport, sedimentation rates are compared to earthflow sediment production rates. Results show a good agreement and demonstrate that earthflows are the primary mass wasting process in these weak rock lithologies. We document best estimates of regional sediment fluxes and related uncertainties. Present earthflow sediment production outpaces Holocene-averaged sedimentation rates by a factor of two. The gap between sediment production and deposition can be partly justified by uncertainties associated with our estimates and by time-scale differences. With this respect, the dynamic equilibrium between erosion and deposition, is likely affected by intra-Holocene oscillations at a short time scale (10 to 1ky) attributable to climate variability. Terraced deposits documenting sedimentary episodes would also support such interpretation. [Copyright &y& Elsevier]

Abstract: Large areas of the Norwegian fjord landscapes are covered by hillslopes that reflect the influence of glacial inheritance from the Last Glacial Maximum (LGM). The focus of this paper is two-fold: (1) analyze the spatio-temporal variability of relevant denudational slope processes and process intensities over the Holocene; and (2) detect Holocene modification of the glacial valley morphometry. Research was performed on hillslope systems within two steep, parabolic-shaped and glacier-fed tributary valleys, Erdalen and Bødalen located on the western side of the Jostedalsbreen ice cap in western Norway. Orthophoto delineation, high resolution mapping (TLS), detailed geomorphological information and spatial data analysis were combined with dating techniques and geophysical investigations. Calculated Holocene rockwall retreat rates at selected slope test sites range from 0.38 to 0.67mmyr−1, with a mean value of 0.53mmyr−1. Slightly higher values were found in Erdalen, with a mean rockwall retreat rate of 0.57mmyr−1 compared to 0.50mmyr−1 in Bødalen. Valley-wide Holocene rockwall retreat rates of 0.38–0.50mmyr−1 are consistent with other estimates of Holocene rockwall retreat rates in cold mountain environments. It is shown that the glacial inheritance of topography is the most important factor controlling valley development since the LGM and that sediment storage capacity is primarily conditioned by valley morphometry. Compared to contemporary rates, the results indicate enhanced denudation activity and intensity immediately following deglaciation and during the ‘Little Ice Age’. The overall tendency of landscape development is postglacial widening of the parabolic-shaped valley morphometry through rockwall retreat with associated debris accumulation beneath rockwalls. As a result, the glacially sculpted topography has not yet adapted to denudational processes acting under Holocene environmental conditions. [Copyright &y& Elsevier]

Abstract: Yardangs are typical wind-eroded landforms that are found in most of the world''s major deserts. This paper describes the morphology of yardangs in the Kumtagh Desert, analyzes their control factors, and discusses their development processes, age, and rates of formation. Yardangs in the Kumtagh Desert lack the ideal streamlined morphology and the length-to-width ratio close to 4:1 that have been previously described as being due to their unique controlling factors, which include a combination of stratigraphic structures, wind erosion and fluvial erosion. Fluvial erosion plays a particularly important role in the development of the yardangs, though wind continuously sculpts their morphology. The development of yardangs can be divided into four stages: an embryonic stage, adolescence, maturation, and recession. Most yardangs in the Kumtagh Desert are in the mature to receding stages. We determined an approximate age for the yardangs based on the erosion rates estimated by several researchers: on this basis, the yardangs in the Kumtagh Desert appear to have formed during the Holocene. [Copyright &y& Elsevier]

In tropical Africa, Late Pleistocene-Holocene climatic fluctuations heavily impacted the continental hydro-systems. The timing and magnitude of 'African Humid Period' hydrological dynamics (AHP; ~14.8 to ~5.5 ka BP) are not yet fully understood due to the extreme variability in African geomorphic patterns and the complex network of past air convergence boundary shifts. The investigation of the functioning of specific hydro-sedimentary basins is needed to improve our knowledge on the AHP spatial and chronological patterns over the continent. In this paper we present a revised Holocene lake level curve of Lake Abhe: an endorheic basin situated in the Afar Depression at the northern extremity of the East African Rift System (EARS). Located at the boundary of the Red Sea and the Indian and Atlantic Oceans' air moisture mass fluxes, the Lake Abhe watershed represents a system sensitive to changes in Northeast African hydro-climate. Based on numerous littoral lacustrine geomorphic features and 53 related radiocarbon ages on stromatolites and nearshore deposits, we have defined the main Holocene lake highstands proposing a detailed paleo-shoreline record. The first rise in water level is dated to ~11.1 ka cal. BP, while the Maximal Holocene Highstand Shoreline (~420 m a.s.l.) was rapidly reached around ~10 ka cal. BP. Evidence of the impact of the 8.2 ka North Atlantic cooling event is recognized with slow lake level regression until ~8.3 ka cal. BP and with an abrupt drop at ~8 ka cal. BP. The resurgence of humid conditions was recorded from ~7.7 ka cal. BP to ~4.6 ka cal. BP. Radiocarbon ages on littoral materials allow us to propose a Holocene subsidence rate of the Abhe basin axial valley. Furthermore, multiphase sill overflow incisions towards the downstream Hanle basin and transient fluvial connectivity with the upstream Ziway-Shala basin, indicate strong geomorphic controls on lake highstand elevations. In summary, Lake Abhe Holocene fluctuations are the result of combined hydro-climatic, tectonic and local geomorphic controls. However, the confrontation with others East African basins allows us to discuss the transport of moisture masses dynamics into the northern EARS during the Holocene. [ABSTRACT FROM AUTHOR]

Coastal morphodynamics and environmental changes have been obviously altered by global warming, sea-level fluctuations, and human activities. Palynological analysis is one of the most important tools for providing information on vegetation, climate, and environmental change, which can be relatively sensitive indicators of human activity during the Holocene. However, Holocene coastal morphodynamics and palynological evidence from the Pearl River Delta and coastal areas has not been sufficiently studied. In this paper, we carry out analyses using detailed grain-size and palynological records of pollen, spores, freshwater algae, and marine dinoflagellate cysts from Borehole QZK13 in the Pearl River Estuary (PRE), southern China. The results show information relating coastal morphodynamics, vegetation evolution, climate changes, and anthropogenic activities during the Holocene based on radiocarbon chronology. In general, the PRE experienced marine transgressive processes; sea-level and the coastline tended to migrate landward between 10,700 and 4250 cal yr BP. Meanwhile, abundant arboreal pollen (mainly Castanopsis , Quercus -evergreen, Oleaceae, and Castanea) and small amounts of non-arboreal pollen (mainly Poaceae, Cyperaceae, and Artemisia) were observed in Borehole QZK13, which suggests that subtropical evergreen broadleaved forests were distributed throughout the PRE and adjacent areas, and relatively warm and moist climatic conditions were present during the early-middle Holocene. After that, there were relatively cool and wet climatic conditions, and marine regressive processes occurred in the PRE during the Late Holocene (ca. 4250–960 cal yr BP) indicated by an abrupt increase in aquatic herbs and Dicranopteris. Moreover, we hypothesize that the Neolithic "cultural fault" in the PRE is likely related to frequent storm surges induced by extreme typhoon events that occurred ca. 3000–2700 yr BP. • Grain size, pollen, spores, freshwater algae and dinoflagellate cysts from the Pearl River Estuary were investigated. • Three major phases shown by palynological results were corresponding to the changes in vegetation and climate. • We hypothesized that the Neolithic "cultural fault" is probably related to the storm surges induced by extreme typhoon events. • Natural vegetation cover has suffered large-scale destruction by ancient humans during the Late Holocene. [ABSTRACT FROM AUTHOR]