Current Projects

QRC members lead and participate in a wide range of disciplinary and interdisciplinary research projects from the study of past earth climates and glaciations to shifts in the geographic distributions and evolution of vegetation and faunal communities, to the evolution and dispersals of the genus Homo and the increasing scales of human modification of earth environments through the Holocene. QRC provides a venue for meeting and collaborating with scholars across Quaternary disciplines. We are also fortunate to be able to provide seed funding and small grants for member research projects. We are especially happy to support grad student and junior scholar research activities, much of which leads to larger, external funding from agencies like the National Science Foundation.


  • 2015-16 | |
    • Jonathan Beyeler, Student
    • Dave Montgomery, Member

    Transient river response to headwater deglaciation, Mount Rainier, WA

    This work seeks to test an idea counter to conventional wisdom regarding the nature and magnitude of glacial fluxes and their role with respect to downstream landform development (e.g., glaciofluvial fans and terraces) as well as climatic oscillations on the timing of landscape evolution (i.e., aggradation versus degradation). Glaciogenic sediment is stored in large moraine complexes built by dynamic alpine glaciers and released when ice retreat debutresses the unstable landforms. Paraglacial sedimentation following deglaciation is the process yet meltwater hydrology is often invoked as the driver of alpine landscape evolution but for unknown durations, with little consideration of flux characteristics (i.e., melt, runoff, and sediments), and with unknown lag times. Little quantitative, mechanistic knowledge exists regarding the processes, controls, timing, and duration of paraglacial sedimentation. By comparing two major glacier-fed rivers at Mount Rainier, WA, this study proposes to elucidate whether meltwater discharge or available glaciogenic sediment fluxes drive downstream transient landform development/degradation through a combination of topographic survey methods, historic discharge and photograph analysis for river response, as well as geophysical methods to quantify sediment supply and storage characteristics. Preliminary data collected in September 2015 from a fixed-wing aircraft for Structure-from-Motion will function as a basemap for geomorphic change detection as well as quantitative rates of change.

  • 2016-17 | |
    • Cassandra Brigham, Student
    • Juliet Crider, Faculty

    Investigating fault scarp degradation in jointed basalt in southern Iceland

    Fault scarps in jointed bedrock hold information key to illuminating a region’s recent tectonic history, such as timing of faulting and magnitude of events, if their morphological evolution through time can be deciphered. This project will investigate how jointed bedrock fault scarps record fault activity and determine the principal drivers of bedrock scarp degradation. This study will focus on characterizing this evolution in basalt-hosted normal fault scarps in southern Iceland, where scarps are abundant and well-exposed. The ongoing oceanic rifting in southern Iceland is marked by late Quaternary-to-recent tectono-volcanic systems identified as the East and West Volcanic Zones (EVZ and WVZ) and is characterized by numerous zones of fissures and faults that affect recent basaltic lava flows. In multiple sites, a single fault cuts through flows of various ages. Close correlation exists between the vertical throw of the major faults and the age of the affected lavas in outcrops, with scarps in Pleistocene flows exhibiting throws of several tens of meters or more and those in Holocene flows less than ten meters. Assuming continuous faulting in this region through the Holocene, we can use the age of the basalt flow as an approximation of the time of scarp formation. The morphology of a scarp from the same fault in each differently aged flow will thus offer a snapshot of its evolution through time, providing the opportunity to establish a space-for-time substitution investigating the tempo and style of scarp growth and degradation along a fault. This study will focus on characterizing the morphology of these bedrock scarps of different ages. We will quantify the degree to which these scarps have retreated through time by measuring the setback between the trace of the scarp in the youngest lava flows and those that preceded it. We will also determine the principal mechanisms of retreat and their timing. The processes that control the retreat of bedrock scarps have been explored in the specific contexts of waterfalls and glacial headwalls, but are still poorly constrained for fault scarps. We hypothesize that scarp degradation is dominated by strong ground motion, with scarps in the more seismically active areas experiencing higher rates of retreat. Cosmogenic exposure dating on a selected scarp will provide the overall retreat rate of the scarp and shed light on the processes that govern its degradation.

  • 2015-16 | |
    • Landon Burgener, Student
    • Kate Huntington, Member

    Spatial Patterns in Terrestrial Paleoclimate Conditions of the Late Cretaceous

    Predicting the response of Earth’s climate to elevated levels of atmospheric CO2 has become an important focus of academic and governmental research (e.g., IPCC, 2013). Development of new paleoclimate reconstruction techniques (e.g., carbonate clumped isotope thermometry) has begun to resolve some of these contradictions between proxies and models, but the application of such proxies has been largely limited to the Paleocene-Eocene Thermal Maximum (PETM). Further work is needed to determine if these proxies and methods are applicable to other greenhouse settings. Reconstructions of Campanian paleoclimate conditions will provide an important contrast to the work done on the PETM, and provide an opportunity to compare and contrast different Greenhouse periods.

    The goal of this project is to advance our understanding of temperature seasonality and precipitation patterns under steady-state greenhouse climate conditions. The results of this project will help resolve long-standing differences between paleoclimate proxy records and model simulations of greenhouse climates. Additionally, by increasing our understanding of climate patterns during Greenhouse climates, this project will have important implications for understanding past climate variations during the Quaternary, and future changes due to anthropogenic climate change.

  • 2016-17 | |
    • Tess Clickingbeard, Student
    • Julian Sachs, Faculty

    Investigating the disappearance of Palau’s jellyfish through Holocene climate reconstructions

    The objectives of this work are to reconstruct the climate of Palau during the last 10,000 years, and to determine the stability of the jellyfish population in Jellyfish Lake during that time. The jellyfish population will be assessed from the abundance of hexadecanoic acid hexadecyl ester, a Mastigias jellyfish-specific biomarker which will be measured down-core in two sets of 13-meter sediment cores collected in September and October 2016, along with the hydrogen isotope composition (2H/1H, or δ2H) and concentration of lipid biomarkers. Hydrogen isotope ratios in microalgal lipids from lake sediments in Palau and elsewhere in the tropics have been shown to be excellent recorders of rainfall and hydroclimate, while the sedimentary abundance of different lipids can be used to reconstruct microbial and microalgal populations of lakes over time. This project aims to reconstruct hydroclimate variations in the West Pacific Warm Pool through the Holocene, a region and time interval that is data depauperate, but nonetheless critical in understanding the global climate system and its response to anthropogenic forcing.

  • 2016-17 | |
    • Camilla Crifo, Student
    • Caroline Stromberg, Faculty

    Using modern phytoliths to determine the spatial resolution of the phytolith fossil record

    Phytoliths have been traditionally used to address a variety of questions in archaeobotany and Quaternary paleoecology. Nevertheless, in the last 15 years phytolith analysis has became a powerful tool for multidisciplinary studies in deep-time paleoecology and evolutionary biology. As the field of phytolith analysis is in expansion, it is crucial that we refine this tool by establishing more rigorous protocols allowing applications and comparisons among a wide range of studies. In line with the currently increasing body of work on phytoliths in modern plants, soil and habitats, my research focuses on phytoliths as a tool to reconstruct habit structure (heterogeneity) in space, across different Neotropical ecosystems (dry forest, rainforest, and savanna). To reconstruct habitat structure in the fossil record, phytolith workers typically rely on the handful of studies indicating that phytolith assemblages can preserve a local habitat signal. However, a systematic effort to test quantitatively the limits of phytolith analysis for resolving spatial patterns in vegetation is lacking; furthermore, methodological issues of previous studies restrict the application of phytolith analysis to specific time scales (Holocene), regions (North America, and Africa), and habitats (grasslands and savannas). The objective of my research is to partially fill the gap in the knowledge of the spatial resolution of the phytolith record in different Neotropical habitats.

  • 2017-18 | |
    • Alison Duvall, Faculty
    • Brian Atwater, Faculty

    Evidence of past M9 events along the coast

    Estuarine evidence for great Cascadia earthquakes: three field trips

    Wednesday, June 6 — Coseismic subsidence and an associated tsunami in 1700. Groundwater eruption ca. 1000, probably unrelated to liquefaction. Copalis River ghost forest (north of Grays Harbor)

    Tuesday, August 14 — Liquefaction in 1700. Mount St. Helens ash from 1479 and probable Bridge of the Gods outburst several decades before. Lower Columbia River (Hunting Island, near Cathlamet)

    Wednesday, August 15 — Seven times of coseismic subsidence in the past 3,500 years. Willapa Bay (Niawiakum River)

  • 2016-17 | |
    • Mikhail Echavarri, Student
    • Peter Lape, Faculty

    San Pablo Archaeological Project.

    This pilot project lays the groundwork for a larger archaeological campaign focused on illuminating indigenous Filipino responses to Spanish colonial intrusions in the Cagayan valley of Northern Luzon. The focal point of the investigation is the church of San Pablo de Cabagan in Isabela province. San Pablo is one of the first established Churches in the region. It therefore has the potential to provide this project with a diachronic data set from pre-colonial to late-colonial eras. This project also aims to be collaborative with the community surrounding San Pablo de Cabagan. As it is still in use today the priest, Father Jomil and several people in the community are interested in the history and conservation of the Church as well. The project plans to share data, conclusions, and to potentially incorporate community originated questions that the archaeology can answer.

    This first pilot field season I will conduct aerial drone survey, test excavation pits, and archival survey to assess the extent of archaeological material in and around the church. Ultimately the larger archaeological investigation into San Pablo de Cabagan has the potential to explore the interplay of colonialism, culture, and environmental change on a local and regional scale.

  • 2016-17 | |
    • Elen Feuerriegel, Student
    • Patricia Kramer, Faculty

    Rock climbing in the Quaternary: A pilot biomechanical study of rock climbing grips compared with under-branch suspensory grips

    The functional morphology of the upper limb and hand in fossil hominins speaks persuasively to the importance of compromise in our evolutionary history. Features indicative morphological commitment to fine prehensile abilities of the hand, and presumably tool behaviors, are balanced with morphologies well-suited to creatures for whom arboreal behaviors form a significant part their locomotor repertoire. Further, these features are coupled with morphological evidence in the lower limb indicative of obligate bipedalism. Historically, the maintenance of more primitive – that is, climbing-advantageous – upper limb features have been interpreted to indicate stabilizing selection for those traits: the continued relevance of an arboreal lifestyle either as a means to escape large cursorial predators, as sleeping sites, or to utilize food resources located in trees.

  • 2017-18 | |
    • Ben Fitzhugh, Faculty

    Defining the Cutting Edge of Quaternary Science: QRC Workshop on Genetic Paleoecology

    The QRC Workshop in Genetic Paleoecology (November 15-16, 2018) will bring together a sample of leading researchers in ancient DNA (aDNA) specializing in the extraction of ancient biological information from a range of contexts (e.g., paleontological, archaeological, botanical, and sedimentary).  Much work in this exploding field has focused on issues of evolutionary phylogeny and paleobiogeography.  To a more limited degree, some researchers are starting to explore the potential for paleoecological analyses using paleogenetic data sets. Some are also tackling previously unexamined issues related to taphonomic and other processes influencing genetic information recovered from these samples.  This workshop is intended to explore these issues through 1) presentations by invited experts from outside of UW; 2) panel and open discussion between those invited experts and UW specialists in related fields; and 3) a brainstorming session to define the “top-20” questions at the forefront of Genetic Paleoecology.  We anticipate that these three activities will provide QRC and other participating students and faculty an opportunity to advance understanding of this growing area of study, provide avenues for those inclined to network and pursue future research using and evaluating the developing approaches.  We hope that bringing these scholars together to explore questions not yet answered will also inspire them and others to anticipate new research needs.  QRC has a nearly 50-year legacy leading and inspiring the field of cutting-edge Quaternary science, especially in the area of paleoecological method, theory and practice. While we don’t currently have QRC faculty working in paleogenomics, we see this workshop as another step to perpetuate this tradition of service to Quaternary science and UW.

  • 2016-17 | |
    • Erin Gamble, Student
    • Ben Fitzhugh, Faculty

    Northern Hokkaido Cultural Chronologies and Environmental Reconstructions from Hamanaka 2, Rebun Island, Hokkaido, Japan

    Excavations at Hamanaka 2, a multi-component archaeological shell-midden located in Northern Japan began in 2011 as part of the joint international efforts of Dr. Andrzej Weber at University of Alberta and Dr. Hirofumi Kato at Hokkaido University. The two main focuses of the project are the life histories of hunter-gatherers using bioarchaeological methods and the formation processes of the Ainu culture. Additionally, the project is interdisciplinary and aims to combine archaeological data with environmental reconstructions of micro-regions. During the 2014 field season, a team from Institute of Geological Sciences, Section Paleontology, Freie Universität Berlin extracted a lake sediment core and collected paleobotanical remains to reconstruct the environmental archive on Rebun Island. While the sediment core has provided 57 radiocarbon dates for analysis with paleoenvironmental data spanning the last c. 17,000 years, the stratified sediment at Hamanaka 2 did not contain enough carbon below layer III to date (Muller et al 2016). Thus leaving most of the sites occupation uncorrelated with the lake core. I propose to use Optical Stimulated Luminescence (OSL) and thermoluminescence (TL) of sediment and pottery, respectively, from Hamanaka 2 to complete the comparison of the core analysis to the archaeological dates discovered on Rebun. My research will contribute “to understanding of late Quaternary climate changes and habitation environments of northern hunter-gatherers in the Hokkaido Region of Japan” (Muller et al 2016). This research also serves as a pilot project for my future dissertation research.

  • 2017-18 | |
    • Alan Gillespie, Faculty
    • Dave Montgomery, Faculty

    GPR transect in the Matanuska – Susitna lowlands, Alaska

    This proposal is for Dave Montgomery and Alan Gillespie to visit QRC member Mike Wiedmer in the field 50 km north of Anchorage this spring, in order to measure ground-penetrating radar transects across landforms behind the Elmendorf terminal moraine.  The goal is to determine what sedimentary structures, if any, are present within the landforms, which resemble giant Rogen moraines or megaflood dunes (as much as 3 km long, 1.25 km wavelength, and 30 m amplitude).  The presence of bedding will help determine if the structures are fluvial, as argued by Wiedmer et al. (2010) in proposing they were evidence of a megaflood; the absence will help support a glacial origin, as originally asserted by Reger and Updike (1983).  This proposal augments an earlier QRC-funded project ($3K) and will allow us to complete that study.

  • 2017-18 | |
    • Joel Gombiner, Student

    A search for pre-LGM megaflood sedimentation in Cascadia Basin

    Marine sediments along the Cascadia margin are likely to contain continuous, long-term records of marine and continental change in the Pacific Northwest over the last several million years. While glaciations, floods, and erosion have reworked the terrestrial record, many marine sites had continuous deposition over this timespan. Such sites are potential archives of oceanographic history, meltwater influx, density-current processes, subduction zone tectonics, and landscape evolution. We propose to study two legacy sediment cores from Cascadia Basin, focusing on depositional chronology and tracers of sediment provenance. The two cores, Deep Sea Drilling Program (DSDP) Sites 174 and 175 are by far the deepest cores from this region, and thus unique in their recovery of sediment spanning multiple glacial-interglacial cycles. This work is a first step towards finding and developing long-term records of megafloods down the Columbia River and understanding Cascadia Basin sedimentation throughout the Pleistocene.

  • 2016-17 | |
    • Bernard Hallet, Faculty
    • Ron Sletten, Faculty

    Freezing soils and patterned ground in the tropics

    Geophysical patterns form spontaneously in diverse settings and environments, in response to non-linear processes. Notable examples include sand dunes and ripples, beach cusps, stalactites, icicles, columnar joints, and patterned ground. These patterns not only attract the eye, but they also stimulate studies that often yield fundamental insights of broad interest [1]. Decades ago, we launched a study of a spectacular example of patterned ground, sorted stripes, near the summit of Mauna Kea (Hawaii) that is absolutely striking because of its geometry regularity (see accompanying photograph).  This study is deeply rooted in QRC; Steve Porter catalyzed it, and it addresses periglacial patterned ground, the principal research interest of QRC’s founder, Lincoln Washburn [2].

    This project will complete the work to date, solidify previous results and complement them with new data that will help 1) bring to fruition perhaps the most comprehensive study of periglacial hillslope activity and self-organization to date, and 2) improve understanding of patterned ground and the motion of surface soil and pebbles on alpine hillslopes. 

  • 2017-18 | |
    • Andrew Hoffman, Student
    • Knut Christianson, Faculty

    Earth Rover – A low budget, expandable, autonomous platform for exploring the Pacific Northwest

    This product, designed to support data collection in unsampled regions of glaciers where high strain rates crevasse the ice surface, and oversteepened tributary walls induce avalanching will expand the sampling capabilities of UW earth scientists in the pacific Northwest. Working with students from UW mechanical engineering, we will build on an established rover design by developing steering vision, and suspension systems that will optimize the rover’s turning efficiency and mobility over uneven mountainous terrain. The final rover product will be deployed on Easton Glacier, measuring surface elevation change via photogrammetry, snow depth and snow water equivalent from ground-penetrating radar, and glacier velocities from stationary rover GPS measurements. The high impact science and research potential of our modular design will enhance collaborations with the UW engineering and the Quaternary Research Center, and our modular configuration extends Earth Rover’s applications beyond the cryosphere. We anticipate applications in other areas of the geosciences, archeology, and civil and environmental engineering. The co-educational development of our terrestrial Rover will bring these disciplines together on a collaborative project that will continue with further rover development and project integration.

  • 2013-14 | |
    • Batbaatar (Bataa) Jigiidsuren, Member

    Dating newly suspected MIS2 moraines in Central Asia by CRN

    Glaciers in Central Asia present an excellent opportunity to test glacier sensitivity to various climate settings. During the global last glacial maximum, around 20,000 years ago, glaciers in southern Siberia and Altay mountains hosted large glacier-dams to originate some of the largest outburst floods on Earth. Central Mongolia shows a similar pattern of glacier advances, in addition to slightly bigger glaciers ~30,000 years ago. In contrast, we have discovered that hyper-arid Gobi glaciated during the warmest period of the early-middle Holocene, with no evidence of glaciations during the coldest of the last ice age. In that condition sunlight provides sufficient energy to evaporate the ice from these precipitation-starved glaciers. This phenomenon was first observed in dry parts of the Kyrgyz Tien Shan, and now we’ve also discovered similar ‘peculiarity’ in the high roofs of Tibet. This project aims to constrain the chronology of glaciers in key locations, and compile a map of paleo-glaciers with different sensitivities.

  • 2015-16 | |
    • Julia Kelson, Student
    • Kate Huntington, Member

    Quantifying Climate Change During The Petm In Continental North America

    The goal of this project is to characterize terrestrial climate change during the Paleocene Eocene Thermal Maximum (PETM). The PETM was a period of rapid warming during a greenhouse climate regime that best resembles the rate of warming occurring in the present, and therefore is a valuable analog to understand Quaternary climate dynamics and future climate change (e.g., Norris & Rohl, 1999; Beerling, 2000; Wing et al., 2005; McInerney & Wing, 2011; IPCC 2013). Paleoclimate proxies that measure how surface temperature and precipitation changed in response to increased atmospheric CO2 in the past are critical to understanding present climate dynamics. By measuring these paleoclimate parameters in paleosols in southwestern Texas with multiple proxies, this project will help resolve longstanding discrepancies between models of greenhouse climates and paleoclimate proxies that have poor spatial and temporal resolution.

  • 2017-18 | |
    • Jiun-Yu Liu, Student
    • Peter Lape, Faculty

    The Emergence of Iron Metallurgy in Taiwan: a Trade Diaspora Model

    My research takes a new approach to investigating the emergence of prehistoric iron metallurgy in Taiwan by using a trade diaspora model, which privileges the role of trade diasporic “foreigner” communities and their interactions with local communities. Trade diaspora are characterized by groups of merchants who travel far from home and locate themselves in a different community to trade goods and provide services. Recently, archaeologists have applied the concept of trade diaspora to explain the interaction between foreign immigrants and indigenous people in historic periods. My project will use the trade diaspora model to explain archaeological data from a time period in Taiwan pre-dating the appearance of documentary historical records, about 1800 years ago.

  • 2017-18 | |
    • Hollis Miller, Student
    • Ben Fitzhugh, Faculty

    The Historical Archaeology of Gender, Food and Labor in Old Harbor, Alaska

    This dissertation project addresses the transformation of Sugpiaq society and identity through the Russian occupation, specifically focusing on gendered patterns of food procurement, preparation and storage in addition to other production tasks in and around Sugpiaq households within the Old Harbor region. The Sugpiat are the indigenous people of the Gulf of Alaska region, including the Kodiak Archipelago, the Alaska Peninsula and Prince William Sound. In framing this project around the period of Russian colonization in Alaska (1784-1867 CE), I consider both social (e.g. resettlement, labor demands) and environmental (e.g. local resource drawdown, epidemic disease) hazards brought on by Russian colonization, which created a multifaceted disaster for the Sugpiaq people – whose vulnerability to these hazards was mediated by factors such as gender, class and marriage status. To address these vulnerabilities and elucidate various Sugpiaq strategies for survival, I combine historical and ethnohistorical documentary research with archaeological analysis. The archaeological research centers on foodways (how people used the environment for subsistence, their menu, food preparation, cooking, eating practices) and the presence and use of both local and imported wares, tools and materials related to other production tasks, such as hide processing, sewing, and RAC-mandated hunts for fur-bearing animals. Taken together, these archaeological materials will provide a picture of daily lives and activities in the Old Harbor region during Russian occupation, which, when put in diachronic comparison, will allow me to trace Sugpiaq identity and the structures of social experience (gender, demographic situation, village and household social organization, religion, etc.) throughout the Russian period.

  • 2013-14 | |
    • Dave Montgomery, Member

    Tibet Moraines Project

    Project summary
    From dating of lake sediments from a QRC trip to NE India, it is clear there were historical floods (e.g., 750 AD), and from the Chinese dating it is clear there were several earlier ones during the Pleistocene. In 2004, samples were collected that allowed dating the times during which there may have been major ice dams across the Yarlong Tsangpo, but most of these samples have not been analyzed as the chronology of glacial damming was outside of the scope of the project that supported the fieldwork. The QRC trip to NE India collected samples of flood deposits that have been dated to the time of the most recent Tibetan lake sediments. This project proposed to date the remaining samples from Tibet using cosmic ray exposure analysis with Be-10 for boulders sampled from moraines and OSL for sands from lake sediment exposures. These data will provide a much-enlarged chronology of ancient glacial river damming (and thus outburst flooding) events that will be of great use for an ongoing project (Huntington/Montgomery) dating the Tsangpo flood deposits in NE India. The goal is to combine our existing dates on Tibetan lake sediments and dated moraine dams collected by Gillespie, Montgomery, and Henck, with downstream flood deposits collected by Larson, Montgomery, and Huntington to write a group QRC paper that ties these observations together (through the dates) and sets the stage for further work in the region.

  • 2017-18 | |
    • Gayoung Park, Student
    • Ben Marwick, Faculty

    Understanding the technological transition during the Late Pleistocene in Korea

    New technology leads new eras of human culture. One of the well-known examples in early human history showing a technological change and its impact on human subsistence is the transition of lithic manufacturing technology during the Late Pleistocene. The transition relates to key issues of human evolution, such as modern human dispersals, the emergence of blade industries and morphologically standardized tools made of stone, bone, antler, and ivory. However, the technological transition of around 40,000 to 30,000 years ago, in East Asia still has many open questions due to the limited number of stone artifact studies and even fewer records of human remains and other material evidence. The proposed research will focus on the transitional period in the Korean Peninsula using models that are built with Cultural Evolutionary theory. The main question is: what are the ecological and social contexts that led to the appearance of new stone artifact technologies in the Late Pleistocene in Korea? I will analyze lithic data from Korea to evaluate models to explain the appearance of new technologies: models of social context (drawing on cultural transmission concepts) and models of ecological context (drawing on behavioral ecology concepts).

  • 2017-18 | |
    • Gerard Roe, Faculty

    Workshop to study hydrologic change over Asia and North America on geological time scales

    As a group, we believe there is value in combining some key periods (perhaps early Neogene, Glacial, and Holocene), the latest proxy indicators of precipitation and aridity (e.g, speleothems, soils, lakes, dust), and some important recent innovations in our theoretical understanding of the hydrologic cycle (much of which originates with UW research). Just to touch on the science: recent UW studies have shown that changes in the zonal-mean hydrologic cycle under increasing CO2 can be understood as a requirement of the down-gradient transport of atmospheric moist static energy (=MSE, the sensible-plus-latent-plus-potential energy). Other recent work (MIT, Yale, UW) has shown the Asian monsoon is driven by zonal asymmetries in the patterns of MSE. We are keen to apply these concepts to paleoclimate states, and believe that the implications for our understanding of paleohydrology would be wide ranging.

  • 2017-18 | |
    • Julian Sachs, Faculty

    Expression of the 8.2 Kyr Event in Palau

    The relatively stable climate of the Holocene epoch (11.7 kyr BP-present) was punctuated by a period of large and abrupt climate change ca. 8.2 kyr BP, when an outburst of glacial meltwater into the Labrador Sea drove large and abrupt climate changes across the globe. However, little is known about the response of the tropical Pacific to this event. This project seeks to characterize the climatic expression of the 8.2 Kyr Event in Palau, western tropical North Pacific by measuring hydrogen isotope (2H/1H, 2H) ratios of microalgal lipids in sediments from Jellyfish Lake on the island of Merchecher and T-Lake on the island of Ngeruktabel. Since 2H values of microalgal lipids in the marine meromictic lakes of Palau have been shown to be sensitive recorders of rainfall we propose to produce a rainfall reconstruction with decadal-to-centennial resolution for the period 9-7 kyr BP. Sediment cores for this project were collected in 2013 and 2016 and initial core descriptions and radiocarbon chronologies have been generated. We hypothesize that the tropical rain band known as the Intertropical Convergence Zone (ITCZ) was driven south by the meltwater flood, as predicted by climate models, and that this resulted in a drying of Palau.

  • 2017-18 | |
    • Hope Sisley, Student
    • Julian Sachs, Faculty

    Rainshadow Effect on Stable Isotopes of n-Alkanes across the Cascade Mountains of Washington, USA

    The Cascade Mountains, which run north-south through Oregon and Washington into British Columbia, are one of the dominant geographic features of the Pacific Northwest.  This project seeks to examine the stable-isotopic orographic rainshadow effect produced by the Cascades by comparing the d2H (dD) and d13C of n-alkanes (a long-chain hydrocarbon found in the waxy cuticles of plant leaves) from living plants, leaf detritus, and soil organic matter in a transect across the Cascades of Washington state.  The dD of a plant is dominantly dependent on the dD of local rainfall, while the d13C depends mainly on the species of the plant and the aridity of its environment; the dD and d13C of n-alkanes in the soil depend on the plants which have contributed leaf litter to that soil.  Documenting how the Cascade rainshadow affects and/or controls hydrogen and carbon isotopic trends is critical to understanding the fate of atmospheric moisture when it passes through orogens, and how plants (and soils) react to those changes.  Moreover, understanding how isotopic trends evolve across the Cascade rainshadow is a mandatory step towards documenting the topographic evolution of the Cascades through geologic time via isotopic proxies.  Identifying the nature of the isotopic trends – for instance, where and how transitions in isotopic composition occur – will allow us to determine if the degree and trend of isotopic depletion is directly correlated to rainshadow intensity and, by extension, the Cascades’ topography. This will provide a dataset for researchers studying isotopic distillation both by plants and by atmosphere dynamics, and a modern comparator for studies of ancient isotopic trends in this and similar settings.

  • 2017-18 | |
    • Li-Ying Wang, Student
    • Ben Marwick, Faculty
    • Julian Sachs, Faculty

    A pilot geochemical analysis of food residues on ancient pottery from Kiwulan, Taiwan

    Our current knowledge of indigenous settlements in northeastern Taiwan suggests a relatively complex social system in the 17th century, around the same time as European contact (Chen 2007; Cheng 2008; Li 2014). I am investigating that whether European contact in this region stimulated a change in indigenous social organization by examining the archaeological evidence at the Kiwulan site (600 to 100 BP, i.e. AD 1400-1900), a major late Iron Age settlement in northeastern Taiwan (Chen 2007). In order to examine the social changes that occurred as a result of the European contact, I am comparing multiple lines of archaeological evidence between the pre-contact and post-contact periods.

     

    This project proposes to further examine one of my foci, locally made pottery, which can reflect prehistoric socioeconomic patterns and enable me to explore the emergence of social inequality. I plan to test the hypothesis that European contact in northeastern Taiwan stimulated a change in social organization, which transformed food consumption at Kiwulan. My model predicts that one of the effects of social-economic inequality induced by European contact was greater differentiation of food consumption after European contact. I will use well-established isotope geochemistry methods to identify the types of foods stored in pots found at Kiwulan.

  • 2016-17 | |
    • Paige Wilson, Student
    • Caroline Stromberg, Faculty
    • Greg Wilson, Faculty

    Climate Change and Plant Response through the Cretaceous-Paleogene (K/Pg) Mass Extinction

    The goal of this study is to understand how ecosystems respond to climate change using the floral record across the Cretaceous-Paleogene boundary in the Hell Creek Area of Montana. Research has shown that the Hell Creek (HC) preserves a rich mammalian and dinosaurian fauna through the Cretaceous-Paleogene (K/Pg) mass extinction. This extinction event occurred 66 million years ago, and led to the extinction of non-avian dinosaurs as well as many other vertebrate, invertebrate, and plant groups. Previous research has focused almost exclusively on the fauna of the HC Area in Montana, and has largely ignored the paleoflora, which can be used both as a record of vegetation change and as a proxy of environmental conditions. These records are additionally complicated by competing theories regarding the magnitude and importance of climate change as a potential cause of the K/Pg mass extinction. This study area provides an opportunity to expand our understanding of this dynamic ecosystem to test the hypothesis that observed faunal extinction coincides with regional climate changes and floral extinctions.

    This project will constitute a new line of investigation into the HC Area, applying novel techniques to test the hypothesis that observed faunal changes (e.g. increasing mammalian diversity and changes in mammal physiology) across the extinction horizon coincide with changes in local environments (such as vegetation structure and composition), and that the observed faunal diversity crisis at the K-Pg was caused by, or exacerbated by, changes in environment. A team will conduct fieldwork in NE Montana over summer 2017 to collect leaf macrofossil and sediment samples at a fine-resolution time series across the K/Pg. This work will be a first portion of ESS graduate student Paige Wilson’s PhD research, in collaboration with Drs. Caroline Strӧmberg and Greg Wilson of the Biology department. These data will help us to test whether there is a record of environmental change across the K/Pg in Montana, whether there is a concurrent record of floral extinction, and how these trends may relate to the larger HC ecosystem and patterns of recent climate change.

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