A5041648549- Geology and Paleoclimatology Research
- Climate change and permafrost
- Cryospheric studies and observations
- Environmental DNA in Biodiversity Studies
- Methane Hydrates and Related Phenomena
- Geological Studies and Exploration
- Arctic and Antarctic ice dynamics
- Microbial Community Ecology and Physiology
- earthquake and tectonic studies
- Geochemistry and Geologic Mapping
- Geological and Geochemical Analysis
- Isotope Analysis in Ecology
- Indigenous Studies and Ecology
- Metabolomics and Mass Spectrometry Studies
- Geological formations and processes
- Archaeology and ancient environmental studies
- Marine and coastal plant biology
- Urban, Neighborhood, and Segregation Studies
- Landslides and related hazards
- Tree-ring climate responses
- Hydrocarbon exploration and reservoir analysis
- Aeolian processes and effects
- Archaeology and Natural History
- Rangeland and Wildlife Management
- Marine and fisheries research
University of Utah
2022-2024
Grantmakers for Effective Organizations
2024
University of California, Santa Cruz
2021-2023
Institute of Arctic and Alpine Research
2017-2022
University of Colorado Boulder
2017-2022
Brookings Institution
2021
University of Colorado System
2014-2020
Carleton College
2011
The use of lake sedimentary DNA to track the long-term changes in both terrestrial and aquatic biota is a rapidly advancing field paleoecological research. Although largely applied nowadays, knowledge gaps remain this there therefore still research be conducted ensure reliability signal. Building on most recent literature seven original case studies, we synthesize state-of-the-art analytical procedures for effective sampling, extraction, amplification, quantification and/or generation...
Abstract. Distributions of branched glycerol dialkyl tetraethers (brGDGTs) are frequently employed for reconstructing terrestrial paleotemperatures from lake sediment archives. Although brGDGTs globally ubiquitous, the microbial producers these membrane lipids remain unknown, precluding a full understanding ways in which environmental parameters control their production and distribution. Here, we advance this three ways. First, present 43 new high-latitude sites characterized by low mean...
Abstract Arctic temperatures are increasing faster than the Northern Hemisphere average due to strong positive feedbacks unique polar regions. However, degree which recent warming is unprecedented remains debated. Ages of entombed plants in growth position preserved by now receding ice caps Canada help address this issue placing conditions a multi-millennial context. Here we show that pre-Holocene radiocarbon dates on collected at margins 30 suggest those locations were continuously covered...
Summer warming is driving a greening trend across the Arctic, with potential for large-scale amplification of climate change due to vegetation-related feedbacks [Pearson et al., Nat. Clim. Chang. (3), 673-677 (2013)]. Because observational records are sparse and temporally limited, past episodes Arctic can help elucidate magnitude vegetation response temperature change. The Last Interglacial ([LIG], 129,000 116,000 y ago) was most recent episode on par predicted 21st century [Otto-Bliesner...
The distribution of brGDGT lipids produced by soil bacteria has been used to reconstruct temperatures in marine and terrestrial settings as far back the Cretaceous period. However, modern calibrations this proxy have primarily relied on air rather than situ temperatures, which can differ more 10 °C. Furthermore, influence other parameters such temperature seasonality chemistry is not fully understood. We measured distributions, pH, water content, electrical conductivity soils from Eastern...
Arctic shrubification is an observable consequence of climate change, already resulting in ecological shifts and global-scale feedbacks including changes land surface albedo enhanced evapotranspiration. However, the rate at which shrubs can colonize previously glaciated terrain a warming world largely unknown. Reconstructions past vegetation dynamics conjunction with records provide critical insights into rates controls on plant migration, but paleoenvironmental reconstructions based pollen...
ABSTRACT 10 Be dating of moraines has greatly improved our ability to constrain the timing past glaciations and thus cold events. However, spread in ages from a single moraine is often greater than would be expected measurement uncertainty, making paleoclimatic interpretations equivocal. Here we present 28 new ice‐cored Neoglacial on Baffin Island, Arctic Canada, explore processes at play formation evolution through field observations numerical debris‐covered glacier model. The insulating...
Abstract. Distributions of branched glycerol dialkyl tetraethers (brGDGTs) are frequently employed for reconstructing terrestrial paleotemperatures from lake sediment archives. Although brGDGTs globally ubiquitous, the microbial producers these membrane lipids remain unknown, precluding a full understanding ways in which environmental parameters control their production and distribution. Here, we advance this three ways. First, present 43 new high-latitude sites characterized by low mean...
Geological evidence indicates that glaciers in the western United States fluctuated response to Holocene changes temperature and precipitation. However, because moraine chronologies are characteristically discontinuous, glacier fluctuations their climatic drivers remain ambiguous, future uncertain. Here, we construct a continuous 10-thousand-year (ka) record of activity Teton Range, Wyoming, using glacial environmental indicators alpine lake sediments. We show persisted some form through...
Abstract Lacustrine δ 2 H and 18 O isotope proxies are powerful tools for reconstructing past climate precipitation changes in the Arctic. However, robust paleoclimate record interpretations depend on site‐specific lake water systematics, which poorly described eastern Canadian Arctic due to insufficient modern data. We use isotopes (δ H) collected between 1994–1997 2017–2021 from a transect of sites spanning Québec‐to‐Ellesmere Island gradient evaluate effects inflow seasonality evaporative...
Abstract Paleotemperature histories derived from lake sediment archives provide valuable context for modern and future climate changes. Branched glycerol dialkyl tetraether (brGDGT) lipids are a tool in such pursuits due to their empirical correlation with temperature near ubiquity nature. However, the relative contributions of terrestrial lacustrine sources brGDGTs sediments is site‐dependent difficult constrain. Here, we explored potential intact brGDGTs—the complete polar head groups...
Abstract. Records of Neoglacial glacier activity in the Arctic constructed from moraines are often incomplete due to a preservation bias toward most extensive advance, Little Ice Age. Recent warming has caused retreat glaciers over past several decades, exposing preserved landscapes complete with situ tundra plants previously entombed by ice. The radiocarbon ages these define timing snowline depression and advance across site, response local summer cooling. Erosion rapidly removes dead that...
Abstract Geologic records of past earthquakes are rare but critical for identifying long‐term patterns in fault behavior and assessing modern earthquake hazards. We present a continuous 14,000‐year paleoearthquake reconstruction using precisely dated lacustrine sediments landslide deposits from lake basin positioned directly on the Teton normal fault, which cuts across Grand National Park, WY, is among most hazardous intraplate faults western United States. show that beginning immediately...
Abstract Sediment cores from 13 lakes in a 1500 km transect along the eastern North American Arctic contain up to four superposed stratified interglacial units. All one unit with sediment similar character and mass Holocene gyttja, 14 C ages >40 ka, luminescence 90 120 pollen assemblages that require nearly complete Laurentide deglaciation, supporting Last Interglacial (LIG; MIS 5e) age. Two preserve an older interglacial, suggesting 7 Four adjacent record thin, organic between LIG units...
Natural grasslands in Alberta are largely used for cattle grazing operations. The abundance of this feeding source is subject to climate variability. Given the large area pasture and (almost 9 million hectares) its value livestock industry Alberta, it would be useful both rangeland managers governments if a insurance program could developed based on satellite imagery. Grazing pastures were monitored throughout province using image data 2002 2003. Normalized difference vegetation index (NDVI)...
Lakes in seismically active regions preserve valuable sedimentary archives of paleoseismic activity within their catchment and beyond. A series glacially-excavated lakes positioned directly along the surface trace Teton normal fault at base Range, WY, are ideally situated to record past since formation approximately 15,000 years ago. Here, we focus on sediment fill contained Jenny Lake (5 km 2 ; 73 m max depth) located bottom Cascade Canyon, central Tetons, where postglacial slip rates...
Research Article| August 01, 2011 Using vertical axis rotations to characterize off-fault deformation across the San Andreas fault system, central California Sarah J. Titus; Titus * 1Department of Geology, Carleton College, One North College Street, Northfield, Minnesota 55057, USA *E-mail: stitus@carleton.edu. Search for other works by this author on: GSW Google Scholar Crump; Crump Zachary McGuire; McGuire USA3Department Western Washington University, 516 High Bellingham, 98225, Eric...