A5008987835- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Landslides and related hazards
- Winter Sports Injuries and Performance
- Climate change and permafrost
- Arctic and Antarctic ice dynamics
- Polar Research and Ecology
- Methane Hydrates and Related Phenomena
- Climate variability and models
- Geological formations and processes
- Isotope Analysis in Ecology
- Atmospheric and Environmental Gas Dynamics
- Pleistocene-Era Hominins and Archaeology
- Seismic Waves and Analysis
- Archaeology and ancient environmental studies
- Icing and De-icing Technologies
- Geological Studies and Exploration
- Meteorological Phenomena and Simulations
- Geophysics and Gravity Measurements
- Tree-ring climate responses
- Paleontology and Stratigraphy of Fossils
- Global Energy and Sustainability Research
- Marine and environmental studies
- Geological and Geochemical Analysis
- Smart Materials for Construction
Pennsylvania State University
2016-2025
University of Kansas
2017
Slippery Rock University
2017
The Ohio State University
1982-2017
Nova Southeastern University
2017
Nanyang Technological University
2017
Center for Remote Sensing and Integrated Systems
2009
University of California, Berkeley
2008
University of California, Irvine
2008
University of Cincinnati
2008
Research Article| June 01, 1997 Holocene climatic instability: A prominent, widespread event 8200 yr ago R. B. Alley; Alley 1Earth System Science Center and Department of Geosciences, Pennsylvania State University, University Park, 16802 Search for other works by this author on: GSW Google Scholar P. A. Mayewski; Mayewski 2Climate Change Center, Institute the Study Earth, Oceans Space, New Hampshire, Durham, Hampshire 03824 T. Sowers; Sowers M. Stuiver; Stuiver 3Department Geological...
Well‐documented present‐day distributions of stable water isotopes (HDO and H 2 18 O) show the existence, in middle high latitudes, a linear relationship between mean annual isotope content precipitation (δD δ temperature at site. Paleoclimatologists have used this relationship, which is particularly well obeyed over Greenland Antarctica, to infer paleotemperatures from ice core data. There is, however, growing evidence that spatial temporal isotope/surface slopes differ, thus complicating...
Geological data indicate that global mean sea level has fluctuated on 103 to 106 yr time scales during the last ∼25 million years, at times reaching 20 m or more above modern. If correct, this implies substantial variations in size of East Antarctic Ice Sheet (EAIS). However, most climate and ice sheet models have not been able simulate significant EAIS retreat from continental size, given atmospheric CO2 levels were relatively low throughout period. Here, we use a model show mechanisms...
Reduction or loss of a restraining ice shelf will cause speed‐up flow from contiguous streams, contributing to sea‐level rise, with greater changes streams that are wider, have stickier beds, higher driving stress. Loss buttressing offsetting half the tendency for ice‐stream/ice‐shelf spreading an stream similar Pine Island Glacier, West Antarctica is modeled contribute at least 1 mm rise over few decades. These results come new, simple model includes relevant stresses in boundary‐layer...
Future sea-level rise is an important issue related to the continuing buildup of atmospheric greenhouse gas concentrations. The Greenland and Antarctic ice sheets, with potential raise sea level approximately 70 meters if completely melted, dominate uncertainties in projected change. Freshwater fluxes from these sheets also may affect oceanic circulation, contributing climate Observational modeling advances have reduced many ice-sheet behavior, but recently detected, rapid ice-marginal...
Large ice sheets actively interact with the rest of climate system by amplifying, pacing, and potentially driving global change over several time scales. Direct indirect influences on cause changes in ocean surface temperatures, circulation, continental water balance, vegetation, land-surface albedo, which turn additional feedbacks help to synchronize change. The effect underlying geological substrate ice-sheet dynamics may be missing link understanding sheet–climate interactions that are...
The Greenland Ice Sheet Project 2 (GISP2) depth‐age scale is presented based on a multiparameter continuous count approach, to depth of 2800 m, using systematic combination parameters that have never been used this extent before. ice at m dated 110,000 years B.P. with an estimated error ranging from 1 10% in the top 2500 core and averaging 20% between m. Parameters date include visual stratigraphy, oxygen isotopic ratios ice, electrical conductivity measurements, laser‐light scattering dust,...
Sea-level rise from melting of polar ice sheets is one the largest potential threats future climate change. Polar warming by year 2100 may reach levels similar to those 130,000 127,000 years ago that were associated with sea several meters above modern levels; both Greenland Ice Sheet and portions Antarctic be vulnerable. The record past ice-sheet indicates rate related sea-level could faster than widely thought.
Analysis of borehole temperature and Greenland Ice Sheet Project II ice-core isotopic composition reveals that the warming from average glacial conditions to Holocene in central was large, approximately 15°C. This is at least three times coincident change tropics mid-latitudes. The coldest periods last were probably 21°C colder than present over ice sheet.
Sulfate concentrations from continuous biyearly sampling of the GISP2 Greenland ice core provide a record potential climate-forcing volcanism since 7000 B.C. Although 85 percent events recorded over last 2000 years were matched to documented volcanic eruptions, only about 30 1 such events. Several historic eruptions may have been greater sulfur producers than previously thought. There are three times as many 5000 two millennia with sulfate deposition equal or up five that largest known...
High-resolution, continuous multivariate chemical records from a central Greenland ice core provide sensitive measure of climate change and composition the atmosphere over last 41,000 years. These series reveal record in relative size intensity circulation system that transported air masses to [defined here as polar index (PCI)] extent ocean cover. Massive iceberg discharge events previously defined marine are correlated with notable expansions cover increases PCI. During stadials without...
Most of the velocity ice stream B near Upstream camp (UpB), West Antarctica, appears to arise from deformation a seismically detected, subglacial till layer that averages 6 m thick. Available evidence indicates entire thickness this is deforming and eroding subjacent bedrock into flutes parallel flow hundreds meters across. The resulting flux beneath UpB equivalent an average erosion rate about 0.4 mm yr −1 in catchment area suggests deltas tens kilometers long have been deposited at...