36 results on '"Petterson, Michael"'
Search Results
2. The role of hope and conservation attitudes in current conservation actions and future conservation intentions
- Author
-
Ough Dealy, Helen R., Jarvis, Rebecca M., Young, Tim, Maharaj, Kushaal, and Petterson, Michael
- Published
- 2024
- Full Text
- View/download PDF
3. The potential for community-driven ecosystem-based disaster risk reduction in South Asia: a literature review
- Author
-
Lansakara, Damithri Chathumani, Le De, Loic, Petterson, Michael, and Wickramasinghe, Deepthi
- Published
- 2024
- Full Text
- View/download PDF
4. Minerals sustainability, emerging economies, the developing world and the ‘truth’ behind the rhetoric
- Author
-
Petterson, Michael G.
- Subjects
sustainable development ,minerals ,geoscience ,copper ,coal ,aggregates ,developed and developing world ,Geology ,QE1-996.5 - Abstract
This paper reviews the principles and applications of sustainable development as applied to minerals (sustainable minerals). The key pillars of sustainable minerals are well known and include economic, community, environmental, and political considerations. The ideal solution is one that finds a balance between community benefit, economic development, profit, and minimal negative environmental and political impacts. This is, of course, fine in theory but in the ‘real world’ difficult to achieve. From a geoscience perspective this paper argues that non-private sector geoscientists have a crucial role to play in developing the sustainable minerals paradigm to an intellectually mature and usable form. The geoscience approach includes re-interpreting the rich legacy of geoscience data and acquisition of new data (geological mapping, 3 and 4D modelling, geophysical and geochemical information) and contextualizing this information with socio-economic and environmental data (e.g. ethnicity, social mix, wealth indicators, environmental sensitivity indicators) to assist with strategic and localized decision-making, maximizing benefits, and minimizing adverse impacts. This approach also involves modelling the full lifecycle of minerals, mines, mineral commodities, and mineral-bearing land in an attempt to quantify benefits and disbenefits of mineral extraction. One crucial key element of a sustainable minerals approach is a mix between ‘hard’ science and social science and genuine inclusion and consultation with stakeholders, especially impacted communities. As geoscientists we are in a position to explain clearly the benefits of mineral development to society and the disbenefits of ‘nimbyism’ (e.g. exporting problems to countries less able to manage mineral extraction) and promote a ‘custodianship’ ethos of mineral development that is the only way to realizing the key principle of sustainability, i.e. leaving the planet in a state that our grandchildren can enjoy.
- Published
- 2008
5. Considering Alternative Reaction Mechanisms: Students' Use of Multiple Representations to Reason about Mechanisms for a Writing-to-Learn Assignment
- Author
-
Watts, Field M., Park, Grace Y., Petterson, Michael N., and Shultz, Ginger V.
- Abstract
Organic reaction mechanisms are often represented by the electron-pushing formalism and reaction coordinate diagrams. These representations pose a challenge to students because valuable information is encoded within each representation, and students must know how to reason about mechanisms using both. Hence, it is important to understand whether and how students consider these two representations when reasoning about reaction mechanisms. We have collected responses to a writing-to-learn assignment administered in a second-semester organic chemistry laboratory course to investigate students' reasoning. The assignment was designed to elicit students' reasoning about the most likely of two mechanisms for a catalyzed intramolecular aldol reaction when given the electron-pushing scheme and reaction coordinate diagram for both mechanisms. As part of the assignment, students submitted initial drafts, participated in content-focused peer review, and submitted revised drafts. We analyzed each component using a mixed methods approach to identify students' reasoning about the most likely reaction pathway and how their reasoning changed after peer review and revision. In this article, we present a quantitative overview of changes students made about their decisions for the most likely reaction pathway and how these changes are related to providing and receiving feedback. Additionally, we present our analysis of the features of representations students used to reason about the likelihood of alternative reaction mechanisms. This study demonstrates how existing research about students' reasoning with representations was operationalized for classroom practice using writing-to-learn. Furthermore, the analysis illustrates how writing-to-learn to can be used to develop students' reasoning and offers implications for teaching students to reason about reaction mechanisms using multiple representations.
- Published
- 2022
- Full Text
- View/download PDF
6. The Role of Authentic Contexts and Social Elements in Supporting Organic Chemistry Students' Interactions with Writing-to-Learn Assignments
- Author
-
Petterson, Michael N., Finkenstaedt-Quinn, Solaire A., Gere, Anne Ruggles, and Shultz, Ginger V.
- Abstract
Student affect is an important factor in the learning process and may be especially important in gateway courses such as organic chemistry. Students' recognition of the relevance of the content they are learning and interactions with their peers can support their motivation to learn. Herein, we describe a study focused on how Writing-to-Learn assignments situate organic chemistry content within relevant contexts and incorporate social elements to support positive student interactions with organic chemistry. These assignments incorporate rhetorical elements--an authentic context, role, genre, and audience--to support student interest and demonstrate the relevance of the content. In addition, students engage in the processes of peer review and revision to support their learning. We identified how the authentic contexts and peer interactions incorporated into two Writing-to-Learn assignments supported students' interactions with the assignments and course content by analyzing student interviews and supported by feedback survey responses. Our results indicate that assignments incorporating these elements can support student affect and result in students' perceived learning, but that there should be careful consideration of the relevance of the chosen contexts with respect to the interests of the students enrolled in the course and the complexity of the contexts.
- Published
- 2022
- Full Text
- View/download PDF
7. Praxis of Writing-to-Learn: A Model for the Design and Propagation of Writing-to-Learn in STEM
- Author
-
Finkenstaedt-Quinn, Solaire A., Petterson, Michael, Gere, Anne, and Shultz, Ginger
- Abstract
Writing is a key disciplinary practice in STEM used to construct scientific knowledge and communicate research findings. With its role in the scientific process, writing is often incorporated into STEM classrooms to train students in scientific writing. The importance of incorporating writing in STEM classrooms is heightened by the role it can play in supporting student learning of disciplinary knowledge and thinking. However, the characteristics of a writing assignment can shape how and what students are learning. Although faculty recognize the value of writing in instruction, they often face barriers that constrain the amount and types of writing they incorporate into their classes. This article describes the design and propagation of Writing-to-Learn assignments in introductory STEM courses at the University of Michigan through the MWrite program. Our aim is to present a framework that could inform similar efforts from the classroom to institutional levels. The Writing-to-Learn assignment design described herein incorporates a context-driven prompt followed by content-focused peer review and revision. We also describe the structures incorporated into the MWrite program to support the large-scale implementation of writing in high-enrollment introductory STEM courses.
- Published
- 2021
- Full Text
- View/download PDF
8. Student Experiences With Peer Review and Revision for Writing-to-Learn in a Chemistry Course Context.
- Author
-
Finkenstaedt-Quinn, Solaire A., Milne, Safron L., Petterson, Michael N., Chen, Jasen, and Shultz, Ginger V.
- Subjects
PEER review of students ,PSYCHOLOGY of students ,FORMATIVE evaluation ,ORGANIC chemistry ,STUDENT surveys - Abstract
Peer review is useful for providing students with formative feedback, yet it is used less frequently in STEM classrooms and for supporting writing-to-learn (WTL). While research indicates the benefits of incorporating peer review into classrooms, less research is focused on students' perceptions thereof. Such research is important as it speaks to the mechanisms whereby peer review can support learning. This study examines students' self-reported approaches to and perceptions of peer review and revision associated with WTL assignments implemented in an organic chemistry course. Students responded to a survey covering how they approached peer review and revision and the benefits they perceived from participating in each. Findings indicate that the assignment materials guided students' approaches during both peer review and revision. Furthermore, students described various ways both receiving feedback from their peers and reading their peers' drafts were beneficial, but primarily connected their revisions to receiving feedback. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Exploring Student Thinking about Addition Reactions
- Author
-
Finkenstaedt-Quinn, Solaire A., Watts, Field M., Petterson, Michael N., Archer, Sabrina R., Snyder-White, Emma P., and Shultz, Ginger V.
- Abstract
Organic chemistry is a required course sequence for many STEM students. However, research indicates that organic chemistry reaction mechanisms are especially challenging for students due to a mixture of underlying conceptual difficulties, the process-oriented thinking inherent to the discipline, and the representations commonly used to depict mechanisms. While student reasoning about many of the reaction types covered in the organic chemistry curriculum has been studied previously, there is minimal research focused specifically on how students think about the mechanisms of addition reactions. Understanding students' conceptions about addition reactions is valuable for both instructors and researchers, as these reactions are among the first for which students must consider different chemical properties to make a decision about alternate reaction pathways. This study provides insight into how students think about these reactions by probing first semester organic chemistry students' thinking using think-aloud interviews as they worked through two addition reactions. To elicit a range of thinking, students worked through the mechanisms using either paper and pencil or an app that dynamically represents the molecules. Generally, students were able to identify the steps of the two addition reactions but did not always successfully apply chemical thinking during the mechanistic steps. Most prominently, both groups of students struggled with the concepts related to carbocation stability, frequently misapplying stabilization via substitution and demonstrating difficulty in identifying the potential for resonance stabilization. Our results suggest that instructors should emphasize the conceptual grounding that directs mechanistic steps, in particular when determining carbocation stability. More generally, our findings suggest that instructors must emphasize the skill of considering and weighing different chemical properties when making decisions about alternative reaction pathways.
- Published
- 2020
- Full Text
- View/download PDF
10. Eliciting Student Thinking about Acid-Base Reactions 'via' App and Paper-Pencil Based Problem Solving
- Author
-
Petterson, Michael N., Watts, Field M., Snyder-White, Emma P., Archer, Sabrina R., Shultz, Ginger V., and Finkenstaedt-Quinn, Solaire A.
- Abstract
An understanding of acid-base reactions is necessary for success in chemistry courses and relevant to careers outside of chemistry, yet research has demonstrated that students often struggle with learning acid-base reaction mechanisms in organic chemistry. One response to this challenge is the development of educational applications to support instruction and learning. The development of these supports also creates an opportunity to probe students' thinking about organic chemistry reaction mechanisms using multiple modalities--i.e., using an app interface or the traditional paper-pencil. This study used think-aloud interviews conducted with undergraduate students in their first semester of organic chemistry to understand how they worked through two acid-base reactions using either paper-pencil or an app. Analysis of the interviews indicates that students from both groups recognize the steps of acid-base reactions, but do not always apply the underlying concepts, such as assessment of pK[subscript a] values or resonance, when determining how a reaction will proceed. The modality seemed to somewhat influence students' thinking, as the app prevented students from making chemically unreasonable mistakes. However, some students relied on the cues it provided, which could potentially be problematic when they are required to respond to assessments that do not provide these cues. Our results suggest that instructors should emphasize the conceptual grounding for the steps that govern acid-base reactions to promote chemical thinking about the relationships between the reaction components and how those influence reaction outcomes, as well as support students to think critically about the chemical information contained within the modalities they are using.
- Published
- 2020
- Full Text
- View/download PDF
11. Interconnected geoscience applied to disaster and risk: case study from SECMOL, Ladakh, N. India
- Author
-
Petterson, Michael, Nanayakkara, Lanka, Konchok, Norgay, Norman, Rebecca, Wangchuk, Sonam, and Linderoth, Malin
- Published
- 2020
- Full Text
- View/download PDF
12. A multiple natural hazard analysis, SECMOL College region, near Leh, Ladakh, North India, with applications for community-based DRR
- Author
-
Petterson, Michael, Wangchuk, Sonam, and Konchok, Norgay
- Published
- 2020
- Full Text
- View/download PDF
13. The Cook Islands (South Pacific) experience in governance of seabed manganese nodule mining
- Author
-
Petterson, Michael G. and Tawake, Akuila
- Published
- 2019
- Full Text
- View/download PDF
14. Can Extractive Industries Make Countries Happy ? What Are Potential Implications for the Geoscientist? Overview and Case Study Examples from Papua New Guinea and Worldwide.
- Author
-
Mosusu, Nathan, Maim, Gideon, Petterson, Michael, Holm, Robert, Lakamanga, Arnold, and Espi, Joseph. O.
- Subjects
MINERAL industries ,INCOME inequality ,GINI coefficient ,HUMAN Development Index ,GROSS domestic product - Abstract
Geoscientists are involved in both the upstream and downstream side of the extractive industries. As explorationists and field geologists, they are often the first technical people related to extractive industries that communities meet. It is imperative in an increasingly globalized and holistic world that geoscientists gain greater awareness of the socio-economic impact of extractive industries and become a more proactive part of improving outcomes for all with respect to extractive industries. When Jigme Singye Wangchuk, the King of Bhutan, first suggested the concept of 'Gross National Happiness' (GNH) in 1972, it was met with widespread cynicism and puzzlement. Was the concept meaningful in a hard, economically competitive world? A series of measures, including the Human Development Index (HDI), the Gini Coefficient (GC), and the now annual World Happiness Report (WHR), are evolutionary responses to the 1972 GNH and are widely accepted as proxy measures of holistic human progress. These measures go beyond the narrow confines of Gross Domestic Product and similar economic proxies, placing economic parameters alongside the social, environmental, spiritual, human rights, health, and holistic societal issues. The broad conclusions of the plethora of metrics are that 'happiness' links to issues and ideas such as equity, minimal economic inequality, excellent governance, human rights, individual freedom, and so forth. We ask the question: what is the relationship between extractive industries (EIs) and GNH? We present a wide range of data and analytical diagrams/text examining potential correlations and associations between GNH and EIs. We examine potential relationships using global data and case studies for Papua New Guinea, Mongolia, the DRC, and Jamaica. The conclusions of this analysis of course suggest a complex relationship between EIs and GNH. We acknowledge that in situations of weak governance and institutions, EIs struggle to make any tangible difference with respect to GNH. A counter conclusion that EIs may even be a major cause of weak governance, which in turn suppresses happiness, must be seriously considered. We document examples where EIs have made a definitive positive improvement to GNH. Data suggest that hydrocarbon-rich countries have made better progress with respect to GNH than mineral-rich countries. However, the main conclusion is that the link between EIs and GNH remains a work in progress, and that a narrow focus on profit and shareholder return is an antithetical approach to the GNH paradigm. A key recommendation is that industry must adopt a far more active role (rather than merely a passive role) with respect to translating the many potential benefits of EIs into GNH than has hitherto been the case. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. The Petrology and Geochemistry of REE-Enriched, Alkaline Volcanic Rocks of Ambitle Island, Feni Island Group, Papua New Guinea.
- Author
-
Ponyalou, Olive L., Petterson, Michael G., and Espi, Joseph O.
- Subjects
GEOCHEMISTRY ,PETROLOGY ,ARCHIPELAGOES ,VOLCANIC ash, tuff, etc. ,VOLCANOLOGY ,METASOMATISM ,PLATINUM group ,VOLCANISM ,MAGNETITE - Abstract
Ambitle in the Feni Island Group is located within the NW trending Tabar–Lihir–Tanga–Feni (TLTF) volcanic island chain, Melanesian Arc, northeastern Papua New Guinea. The TLTF chain is renowned for its alkaline magmatism, geothermal activity, copper–gold mineralization, and world-class gold mining. Although its geochemical patterns indicate island arc signatures (i.e., high LILE and depleted HFSE), TLTF volcanism is not directly related to the older Melanesian Arc subduction system. However, it may have been influenced by source mantle metasomatism linked to the older subduction. The purpose of this study is to (1) present and interpret the petrographic, mineralogical, and geochemical data from Feni within the context of the tectonic evolution of the TLTF and (2) propose a geodynamic, petrogenetic model for the Feni volcanic rocks. The key methodologies used in this study are field mapping and sampling, petrographic analysis using the optical microscope, whole-rock geochemical analysis via XRF and ICP MS, and mineralogical analysis using an electron microprobe. The main rock types sampled in this study include feldspathoid-bearing basalt, trachybasalt, phonotephrite, trachyandesite, and trachydacite. Minerals identified include forsteritic olivine, diopside, augite, labradorite, andesine, anorthitic plagioclase, nepheline, and leucite in the primitive mafic suites, whereas the more evolved intermediate and felsic hypabyssal suites contain amphibole, albite, orthoclase, biotite, and either rare quartz or feldspathoids. Amphibole composition is primarily magnesiohastingsite with minor pargasite formed under polybaric conditions. Accessory minerals include apatite, titanite, and Ti-magnetite. We propose that limestone assimilation followed by fractional crystallization are plausible dominant processes in the geochemical evolution of the Ambitle volcanics. Clinopyroxene fractionation is dominant in the mafic volcanics whereas hornblende fractionation is a major petrologic process within the intermediate suites proven by the enrichment of LREE and depletions in MREE and HREE. Feni magmas are also highly enriched in REEs relative to neighboring arcs. This study is globally significant as alkaline magmas are important sources of Cu, Au, and REE as critical elements for green energy and modern technology. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
16. The Geological and Tectonic Evolution of Feni, Papua New Guinea.
- Author
-
Ponyalou, Olive L., Petterson, Michael G., and Espi, Joseph O.
- Subjects
METASOMATISM ,ARCHIPELAGOES ,VOLCANOLOGY ,TRACHYTE ,VOLCANIC ash, tuff, etc. ,GEOLOGY ,GEODYNAMICS - Abstract
Feni is located at the southeastern end of the NW-trending Tabar–Lihir–Tanga–Feni (TLTF) volcanic island chain, in northeastern Papua New Guinea. This island chain is renowned for hosting alkaline volcanics, geothermal activity, copper–gold mineralization, and mining. There is no agreed consensus on the tectonic and petrogenetic evolution of Feni. Thus, the purpose of our paper is to present the geology of Feni within the context of the regional tectonic evolution of the TLTF chain and offer a succinct and generic geodynamic model that sets the stage for our next paper. The methodologies used in this study include a critical review of published and unpublished literature in conjunction with our geological observations on Feni. The Pliocene-to-Holocene TLTF chain is a younger arc situated within the greater Eocene-to-Oligocene Melanesian Arc bounded by New Ireland to the west, the Kilinailau Trench and Ontong Java Plateau in the east, and the New Britain Trench to the south. The geological units mapped on Feni include a large volume of basaltic lava flow and trachyandesite stocks intruding a limestone and siltstone basement. Younger units include the trachyte domes, pyroclastic flow, and ash fall deposits. The major structures on Feni are normal or extensional faults such as the Niffin Graben. Feni magmatism is attributed to the petrogenetic processes of polybaric or decompression melting and crystal fractionation of magmas previously influenced by sediment assimilation, mantle wedge metasomatism, slab tears, slab melts, and subduction. Deep lithospheric normal faults provide the fluid pathways for the Feni alkaline magmas. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
17. Digital Tools for the Promotion of Geological and Mining Heritage: Case Study from the Thames Goldfield, Aotearoa, New Zealand.
- Author
-
Cocal-Smith, Vanessa, Hinchliffe, Graham, and Petterson, Michael G.
- Subjects
GOLD mining ,DIGITAL technology ,MINES & mineral resources ,ARCHIPELAGOES ,GOLD ores ,WEB-based user interfaces ,DIGITAL media - Abstract
The geoheritage value in the Thames District, North Island, New Zealand, is notable for its over 50 epithermal gold deposits associated with the Coromandel Volcanic Zone, significant to the region's geological, cultural, and mining heritage. This case study was conducted in collaboration with the Thames School of Mines and Mineralogical Museum to develop a series of web-based applications for public outreach and an accessible museum experience through the utilization of specimens from the mineralogical museum. This research applies a conceptual framework of ex situ geoheritage to explore links between local geology with cultural and mining heritage. Minerals and rock specimens collected for the Thames School of Mines Mineralogical Museum were used to create 3D virtual models demonstrating the epithermal mineralization in the Thames Goldfield. Outputs of this project consist of two digital products, including a digital mineral and rock repository and the dissemination of the geological collection through integrating the photogrammetric models into a user-friendly outreach, ArcGIS Storymaps, to depict the geoheritage relationship of the specimens to regional gold mining, and at the same time, to be developed to be implemented in geoscience education and communication. The results of this paper are intended to promote the use of digital tools for enhancing and raising awareness of the geoheritage values of the Thames Goldfield. This approach has relevance for Papua New Guinea and the Pacific Islands in raising awareness of geological, mineral, and mining heritage within widely distributed and often isolated communities across island archipelago nations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. Analysing Civilian Video Footage for Enhanced Scientific Understanding of the 2011 Tohoku Earthquake and Tsunami, Japan, with Implications for PNG and Pacific Islands.
- Author
-
Mcdonough-Margison, Caitlin, Hinchliffe, Graham, and Petterson, Michael G.
- Subjects
SENDAI Earthquake, Japan, 2011 ,TSUNAMI warning systems ,TSUNAMIS ,FLOW velocity ,STORM surges ,ISLANDS - Abstract
Approximately 70% of global tsunamis are generated within the pan Pacific Ocean region. This paper reports on detailed analysis of civilian video footage from the 2011 Tohoku earthquake, Japan. Comprehensive scientific analysis of tsunami video footage can yield valuable insights into geophysical processes and impacts. Civili22an video footage captured during the 2011 Tohoku, East Honshu, Japan tsunami was critically examined to identify key tsunami processes and estimate local inundation heights and flow velocity in Kesennuma City. Significant tsunami processes within the video were captured and orientated in ArcGIS Pro to create an OIC (Oriented Imagery Catalogue). The OIC was published to ArcGIS Online, and the oriented imagery was configured into an interactive website. Flow velocity was estimated by quantifying the distance and time taken for an object to travel between two known points in the video. Estimating inundation height was achieved by taking objects with known or calculable dimensions and measuring them against maximum local inundation height observations. The oriented imagery process produced an interactive Experience Builder app in ArcGIS Online, highlighting key tsunami processes captured within the video. The estimations of flow velocity and local inundation height quantified during video analysis indicate flow speeds ranging from 2.5–4.29 m/s and an estimated maximum local run-up height of 7.85 m in Kesennuma City. The analysis of civilian video footage provides a remarkable opportunity to investigate tsunami impact in localised areas of Japan and around the world. These data and analyses inform tsunami hazard maps, particularly in reasonably well-mapped terrains with remote access to landscape data. The results can aid in the understanding of tsunami behaviours and help inform effective mitigation strategies in tsunami-vulnerable areas. The affordable, widely accessible analysis and methodology presented here has numerous applications, and does not require highly sophisticated equipment. Tsunamis are a significant to major geohazard globally including many Pacific Island states, e.g., Papua New Guinea, Solomon Islands, and Tonga. Video footage geoscientific analysis, as here reported, can benefit tsunami and cyclone storm surge hazards in the Pacific Islands region and elsewhere. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. Granites of the Southern Mongolia Carboniferous Arc: New geochronological and geochemical constraints
- Author
-
Blight, James H.S., Crowley, Quentin G., Petterson, Michael G., and Cunningham, Dickson
- Published
- 2010
- Full Text
- View/download PDF
20. Tumbi Landslide, Papua New Guinea: rainfall induced?
- Author
-
Robbins, Joanne C., Petterson, Michael G., Mylne, Ken, and Espi, Joseph O.
- Published
- 2013
- Full Text
- View/download PDF
21. Crustal evolution of the Saykhandulaan Inlier, Mongolia: Implications for Palaeozoic arc magmatism, polyphase deformation and terrane accretion in the Southeast Gobi Mineral Belt
- Author
-
Blight, James H.S., Cunningham, Dickson, and Petterson, Michael G.
- Published
- 2008
- Full Text
- View/download PDF
22. The Oyut Ulaan Volcanic Group: stratigraphy, magmatic evolution and timing of Carboniferous arc development in SE Mongolia
- Author
-
Blight, James H.S., Petterson, Michael G., Crowley, Quentin G., and Cunningham, Dickson
- Subjects
Mongolia -- Environmental aspects ,Mongolia -- History ,Volcanism -- Research ,Geology, Stratigraphic -- Research ,Earth sciences - Abstract
The Palaeozoic--Mesozoic tectonic evolution of Central Asia, including the vast terrane collage that makes up Mongolia, has been a topic of considerable debate. The Oyut Ulaan Volcanic Group is a sequence of volcanic and sedimentary rocks in SE Mongolia that forms the southern part of the Devonian-Permian Saykhandulaan Inlier. Fieldwork traverses and mapping have established four distinct formations in the Oyut Ulaan Volcanic Group that record the nature of arc activity in part of the Central Asian Orogenic Belt during the Carboniferous. Physical volcanological and sedimentological characteristics of the four formations suggest three clear eruptive styles: (1) periodic andesite volcanism in an actively eroding arc setting that also contained large rivers and swamps; (2) highly effusive plateau andesite volcanism; (3) explosive rhyolitic effusion. Geochemical analyses of volcanic lithologies suggest that the group represents subduction-related, mature, continental arc volcanism. Geochemical results document an evolving magma system to which surface processes of the volcano-sedimentary model may be linked. Magma pulses and replenishments are identified from variations in chemostratigraphy. Newly obtained zircon ages from the volcanic succession fix its emplacement (eruption) at 323.0 [+ or -] 0.7 Ma (mid-Carboniferous or late Mississippian). A granite cobble from the lower part of the Oyut Ulaan Volcanic Group gives a U--Pb zircon age of 338.9 [+ or -] 0.4 Ma indicating that arc plutons were emplaced 10 Ma prior to the Oyut Ulaan volcanism and were eroded soon after. Our work provides timing constraints for final accretion and continental assembly in SE Mongolia, and also sheds light on the petrological development of a magmatic arc system within an evolving accretionary orogen. doi: 10.1144/0016-76492009-094.
- Published
- 2010
23. Masimo Signal Extraction Pulse Oximetry
- Author
-
Goldman, Julian M., Petterson, Michael T., Kopotic, Robert J., and Barker, Steven J.
- Published
- 2000
- Full Text
- View/download PDF
24. A re-evaluation of the stratigraphy and evolution of the Kohistan arc sequence, Pakistan Himalaya: implications for magmatic and tectonic arc-building process
- Author
-
Treloar, Peter J., Petterson, Michael G., Jan, M. Qasim, and Sullivan, M.A.
- Subjects
Himalaya Mountains -- Natural history ,Geology, Stratigraphic -- Research ,Magmatism -- Research ,Plate tectonics -- Research ,Earth sciences - Abstract
New field mapping and structural data, combined with published geochemical data, from the Kohistan arc in the NW Himalaya, enable a re-evaluation of the arc stratigraphy. Key lithological units and their relationships are more clearly defined, permitting the construction of a revised magmatic-tectonic history for the arc. The oldest units are transitional oceanic-type basalts, which form the basement to the subduction related sequence. Arc-type gabbroic sheets and plutons intrude the oceanic basalts: together these form the Kamila Amphibolite Belt. Metasediments and basaltic lavas were deposited, within an extensional basin, onto the Kamila Amphibolite Belt basement. This sequence, exposed across the arc, forms a distinct stratigraphic unit which is formally defined here as the Jaglot Group. Sediment-charged turbidity currents transported material into the basin, whilst submarine eruptions contributed the basaltic component. This period of extension culminated in the eruption of high-Mg boninites of the Chalt Volcanic Group which overlie the rocks of the Jaglot Group. The earliest granitoids of the Kohistan Batholith predate suturing and intrude the Jaglot and Chalt sequences. At c. 100 Ma Kohistan sutured to Asia, suturing being accompanied by thickening of the arc with the development of major intra-arc shear zones and a penetrative, regionally developed steep cleavage. At c. 85 Ma intra-arc rifting permitted the emplacement into the arc of the voluminous gabbronorites of the Chilas Complex which clearly intrudes the Kamila Amphibolite Belt to the south and the Jaglot Group to the north. The Chilas Complex has been regarded as part of the pre-suturing, juvenile arc sequence. Field evidence summarized here show this to be not so. Heat advection associated with emplacement of the Complex caused amphibolite facies regional metamorphism, melting of the lower arc and plutonism. Some of the resultant granitoid plutons were unroofed and eroded during a compressional phase at between 80 and 55 Ma, before emplacement of further plutons and extrusion of basaltic through to rhyolitic volcanic rocks at between 55 and 40 Ma. At least three phases of extension and rifting, each separated by short lived phases of compression, characterized arc evolution. Much of the magmatism is controlled by extensional tectonics within the overriding plate of the kind commonly associated with a retreating subduction zone. Keywords: Himalaya, Pakistan, Kohistan, island arcs, igneous activity.
- Published
- 1996
25. Innovative ways of illustrating the present, imagining the future and analysing themes: A collage-elicited interview study.
- Author
-
Ough Dealy, Helen R, Jarvis, Rebecca M, and Petterson, Michael
- Subjects
PREDATORY animals ,URBAN community development ,ENVIRONMENTAL education ,METHODOLOGY - Abstract
Mammalian predators are threatening New Zealand's endemic species with extinction. Community-led predator control may contribute to a predator-free nation by 2050. An individual's present and future thoughts about, and subsequent actions for, conservation rely on their current and projected motivations and concerns. Innovative approaches to conservation action theme elicitation and analysis were developed through this visual arts based qualitative study to better understand how people feel about the present and future and their place within. Twenty-five males and females from New Zealand's rural and urban communities, aged between 12 and 75 years, from primary, secondary and tertiary student, environmental education and community conservation backgrounds, each created two collages of themselves situated in today's and a future world. Interviewer-led open-ended laddering questions elicited participant responses to their collages. A further open-ended question elicited actions participants would take to move from their perceived present to a projected future world. Trello, a web-based list-making application, facilitated reflexive thematic analysis of the interview transcripts. The following six common themes resulted: connectivity, commitment, learning cycle, practical actions, unconditional belief and group action. These themes, presented as eight-point Likert-type scale items in a Qualtrics digital survey, contributed to the quantitative aspect of this mixed-methods study and may facilitate understanding of future New Zealand volunteer community conservation participation. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
26. The geological history and hazards of a long-lived stratovolcano, Mt. Taranaki, New Zealand.
- Author
-
Cronin, Shane J., Zernack, Anke V., Ukstins, Ingrid A., Turner, Michael B., Torres-Orozco, Rafael, Stewart, Robert B., Smith, Ian E. M., Procter, Jonathan N., Price, Richard, Platz, Thomas, Petterson, Michael, Neall, Vince E., McDonald, Garry S., Lerner, Geoffrey A., Damaschcke, Magret, and Bebbington, Mark S.
- Subjects
DEBRIS avalanches ,DENSITY currents ,PUMICE ,MAGMAS ,HAZARDS - Abstract
Mt. Taranaki is an andesitic stratovolcano in the western North Island of New Zealand. Its magmas show slab-dehydration signatures and over the last 200 kyr they show gradually increasing incompatible element concentrations. Source basaltic melts from the upper mantle lithosphere pond at the base of the crust (∼25 km), interacting with other stalled melts rich in amphibole. Evolved hydrous magmas rise and pause in the mid crust (14–6 km), before taking separate pathways to eruption. Over 228 tephras erupted over the last 30 kyr display a 1000–1500 yr-periodic cycle with a five-fold variation in eruption frequency. Magmatic supply and/or tectonic regime could control this rate-variability. The volcano has collapsed and re-grown 16 times, producing large (2 to >7.5 km
3 ) debris avalanches. Magma intrusion along N-S striking faults below the edifice are the most likely trigger for its failure. The largest Mt. Taranaki Plinian eruption columns reach ∼27 km high, dispersing 0.1 to 0.6 km3 falls throughout the North Island. Smaller explosive eruptions, or dome-growth and collapse episodes were more frequent. Block-and-ash flows reached up to 13 km from the vent, while the largest pumice pyroclastic density currents travelled >23 km. Mt. Taranaki last erupted in AD1790 and the present annual probability of eruption is 1–1.3%. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
27. Pulse oximetry: Analysis of theory, technology, and practice
- Author
-
Wukitsch, Michael W., Petterson, Michael T., Tobler, David R., and Pologe, Jonas A.
- Published
- 1988
- Full Text
- View/download PDF
28. Volcanostratigraphy of arc volcanic sequences in the Kohistan arc, North Pakistan: volcanism within island arc, back-arc-basin, and intra-continental tectonic settings
- Author
-
Petterson, Michael G. and Treloar, Peter J.
- Subjects
- *
VOLCANOES , *ANDESITE , *VOLCANIC ash, tuff, etc. - Abstract
The Kohistan arc was initiated, offshore of Asia, during the mid-Cretaceous above northward subducting, Tethyan oceanic crust. The arc sutured to Asia c. 90 Ma ago. Subduction of oceanic crust beneath the arc continued until Indian Plate continental rocks began to underthrust the arc c. 50 Ma ago. The arc shows an evolutionary history from the juvenile stages of an intra-oceanic island arc, through a thickened Andean-style volcanic arc accreted to a continental margin, to an arc underplated by older continental crust. Extrusive volcanic activity spanned the mid-Cretaceous to Oligocene. This paper presents new and detailed lithostratigraphic data relating to two volcanic groups. The mid-Cretaceous Chalt Volcanic Group (CVG) documents volcanism in the last stages of the island arc phase. The Eocene-Oligocene Shamran Volcanic Group (SVG) documents Andean margin to post-Himalayan collision volcanism. The CVG comprises two formations, formally defined here. The back-arc Hunza Formation is dominated by subaqueous back-arc effusive basalt, andesite and boninite volcanism with a brief phase of subaerial silicic volcanism. The intra-arc Ghizar Formation comprises basalt and andesite-dominated crystalline and volcaniclastic rocks produced by subaerial and subaqueous calc-alkaline arc stratovolcano and shield eruptions. Two facies are present: a basalt and andesite lava flow-dominated sequence and a volcaniclastic-dominated sequence with characteristics that indicate effusive-explosive volcanism and subsequent volcanic sediment reworking and deposition within both subaqueous and subaerial settings. A stratovolcanic centre in the Ishkoman Valley contains abundant proximal volcanic lithofacies suggestive of Strombolian–Vulcanian explosive eruptive activity. The SVG, which unconformably overlies deformed rocks of the CVG, crops out in relatively small, high-altitude outliers. Previous suggestions that it has a large outcrop area in western Kohistan are unfounded. The SVG is an undeformed sequence of reddened, dominantly silicic volcanic rocks comprising mainly andesitic to dacitic and rhyolitic lavas, parataxitic and eutaxitic welded silicic ignimbrites, poorly sorted volcaniclastic sandstones, conglomerates and tuffs, and well-sorted, very fine-grained vitric tuffs. The SVG records highly evolved explosive and effusive volcanism within a mature Andean continental margin to post-Himalayan collisional environment. Primary magmas were probably generated at c. 40–30 Ma within relict metasomatised Tethyan mantle wedged between the Kohistan arc above and the underplating Indian Plate below. [Copyright &y& Elsevier]
- Published
- 2004
- Full Text
- View/download PDF
29. The Suitability of the Pacific Islands for Harnessing Ocean Thermal Energy and the Feasibility of OTEC Plants for Onshore or Offshore Processing.
- Author
-
Kim, Hyeon-Ju, Lee, Ho-Saeng, Lim, Seung-Taek, and Petterson, Michael
- Subjects
OCEAN ,CLEAN energy ,SUPPLY & demand ,SUSTAINABLE development ,SEAWATER ,OCEAN mining ,HYDROGEN as fuel ,TUNA fisheries - Abstract
Ocean Thermal Energy Conversion (OTEC) relies on the thermal differences between ocean surface waters and cooler waters at c. 1000 m depth. The highest and most reliable thermal differentials are in the low latitudes, 20° either side of the equator, including the Pacific Islands region. Whilst in theory OTEC can utilize an inexhaustible amount of stored energy within the oceans, in practice the industry remains in its technical infancy, but with an increasing relevance to a post-fossil-fuel, environmentally conscious world. OTEC does not only produce electricity. OTEC-seawater utilization technologies produce high demand ocean minerals, desalination, a range of waters for aquaculture and hydroponics, and have the potential to produce large quantities of green hydrogen. OTEC is a green energy and could revolutionize the energy and economic landscape of Pacific island countries, providing reliable low-C electricity and a basis for a range of industry. This paper analyses the economics of using OTEC in combination with existing and potential future industries of importance to the Pacific (and other oceanic) regions, including tuna fisheries, seabed minerals and green hydrogen. The conclusions of these analyses suggest that OTEC has the potential to minimize carbon emissions, increase efficiencies, and create new high-quality green-technology industries and livelihoods. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Securing the Limits of Large Ocean States in the Pacific: Defining Baselines Limits and Boundaries amidst Changing Coastlines and Sea Level Rise.
- Author
-
Bernard, Leonardo, Petterson, Michael, Schofield, Clive, and Kaye, Stuart
- Subjects
SEA level ,COASTAL changes ,MARITIME boundaries ,OCEAN ,CORAL reefs & islands - Abstract
The Pacific Island States and Territories are traditionally described as 'small island' nations. However, they are also 'large ocean' nations with jurisdiction over substantial maritime spaces stretching to at least 200 nautical miles. The article addresses issues related to baselines along the coast on which these broad maritime claims depend. The article then examines geodynamic considerations coupled with sea and land level projections in the Pacific leading to an assessment of the vulnerability or resilience of atolls in particular. The article then discusses potential implications for the coastlines and baselines of the Pacific Island States and Territories, the limits of their maritime entitlements and both delimited and undelimited maritime boundaries. Potential response options, prospects, and concluding thoughts are then offered. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Why Disaster Subcultures Matter: A Tale of Two Communities: How and Why the 2007 Western Solomon Islands Tsunami Disaster Led to Different Outcomes for Two Ghizo Communities.
- Author
-
Hagen, Kim, Petterson, Michael G., Humphreys, David, and Clark, Nigel
- Subjects
SOCIAL science research ,TSUNAMIS ,TSUNAMI warning systems ,SUBCULTURES ,ISLANDS ,DISASTERS ,PROPERTY rights ,MINORITY stress - Abstract
At 07:45 a.m. on 2 April 2007, a tsunami hit Ghizo Island, western Solomon Islands in the south-west Pacific. Thirty-three people died on Ghizo, of whom 31 originated from a relatively small migrant Gilbertese community (transmigrated in the 1950s–1970s from Kiribati), while only two were from the majority Melanesian community. This paper documents an extensive 4-year study that addresses the potential core reasons for this asymmetrical casual impact. Community-participatory social science research was undertaken in two Gilbertese villages and two Melanesian villages. The four villages had similar spatial vulnerabilities due to their coastal location, although they had variable access to the safer higher ground. Gilbertese villages had less diverse ocean-reliant livelihoods, a limited knowledge of hinterland bush resource utilisation, uncertainties regarding land rights, and perceived ethnic discrimination. Melanesian villages had strong wantok and kastom social reciprocity cultures, a diverse set of livelihoods, wider social capital with other Melanesian communities, and greater security regarding land rights. This paper argues that these key factors—linked to the lower status as a migrant community of the Gilbertese, a limited sharing of knowledge between communities, government blind spots and power hierarchies—explain both the disproportionate impacts of the disaster and issues that impact longer-term aid intervention and social cohesion. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
32. Stream Sediment Datasets and Geophysical Anomalies: A Recipe for Porphyry Copper Systems Identification—The Eastern Papuan Peninsula Experience.
- Author
-
Mosusu, Nathan, Bokuik, Angela, Petterson, Michael, and Holm, Robert
- Subjects
PORPHYRY ,SYSTEM identification ,COPPER ,MAGNETIC anomalies ,GEOPHYSICS ,RIVER sediments ,GOLD - Abstract
Airborne magnetic and radiometric datasets have, over the past few years, become powerful tools in the identification of porphyry systems which may host economic porphyry copper–gold–molybdenum ore bodies. Magnetisation contrasts with the unaltered host rocks, coupled with the elevated radiometric signature, compared to the host rock, makes identification of large-scale porphyry copper systems possible. Integrating these two different datasets with stream sediment data and other geochemical exploration methods results in a higher degree of confidence. Stream sediment data were analysed to see the distribution of copper and gold elements throughout the study area, located within the Eastern Papuan Peninsula of Papua New Guinea. Airborne geophysics data over the same area were also processed for magnetic and radiometric responses. The processing of the magnetic data revealed several magnetic anomalies related to concealed intrusive rock units, with associated radiometric signatures. The distribution of gold and copper anomalism was correlated with the geology and geophysical signatures. Results indicate varying degrees of correlation, with some areas showing a strong correlation between gold/copper occurrence and geophysical signatures, compared to other areas. Some factors that we believe impact the level of correlation may include tectonic history, volcanic cover, and weathering patterns. We recommend caution when applying multi-data exploration for porphyry copper systems. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
33. O cei na Vulavula ? Insights and Regrets of a Foreign Geoscientist in the Pacific Islands.
- Author
-
Nunn, Patrick D., Petterson, Michael G., and Martinez-Frias, Jesus
- Subjects
GEOLOGY ,EARTH sciences ,LANDSCAPES ,RADIOCARBON dating - Abstract
From over three decades of close contact with Pacific Islands geoscience, the author reflects on key issues (what he wished he had known earlier) about the nature of islands, their landscapes and their peoples. Experience elsewhere in the world rarely prepares you for the Pacific, from its youthful and often tectonically unstable landscapes to the understandings of its inhabitants, which are sometimes time-consuming and difficult to access yet frequently illuminating. Mysteries abound in Pacific geoscience, often in places as difficult to access as they ever were, yet which have the potential to inform global ideas about earth-surface evolution. Geoscience research and enterprise remain largely foreigner-driven in the Pacific Islands, which is often anathemic to sustainability, privileging ideas that are uncritically assumed to be shared by their peoples. An opportunity exists for Pacific peoples to own the geoscientific knowledge and potential of their islands. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
34. Minerals sustainability, emerging economies, the developing world, and the 'truth' behind the rhetoric.
- Author
-
Petterson, Michael G.
- Subjects
- *
MINERALS , *NONRENEWABLE natural resources , *SUSTAINABLE development , *GEOLOGY , *EARTH sciences - Abstract
The article focuses on sustainable development of nonrenewable mineral resources. It is noted that the development involves extraction and usage of resources for present use which is bound to cause a reduction in the resources for the future generation. The application of sustainable mineral development requires that the geoscientific information be reinterpreted. It stresses the need to ensure that past mining practices and their negative impact on the environment are not repeated.
- Published
- 2007
- Full Text
- View/download PDF
35. Rb [sbnd]Sr dating of the Kohistan arc-batholith in the Trans-Himalaya of north Pakistan, and tectonic implications
- Author
-
Petterson, Michael G. and Windley, Brian F.
- Published
- 1985
- Full Text
- View/download PDF
36. Microphones and feedback suppression in teleconferencing.
- Author
-
Petterson, Michael and Julstrom, Steve
- Abstract
The effect of room acoustics on microphone placement and selection for teleconferencing systems and current approaches to electroacoustic feedback and echo control in teleconferencing systems will be discussed. [ABSTRACT FROM AUTHOR]
- Published
- 1989
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.