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Full-Text Articles in Physical Sciences and Mathematics
Collaborative Research: Sensitivity Of Local Glaciers In Central East Greenland To Holocene Climate Change, Brenda Hall
Collaborative Research: Sensitivity Of Local Glaciers In Central East Greenland To Holocene Climate Change, Brenda Hall
University of Maine Office of Research Administration: Grant Reports
This award will support an investigation of Holocene glacier fluctuations in the Scoresby Sund region of central East Greenland (~70-72¿N, 22-28¿W) along a transect from a coastal maritime setting to the continental conditions adjacent to the Greenland Ice Sheet. The 'Intellectual Merit' of the proposed study lies in the potential to affirm, or otherwise, the widely-held view that the scale of glacier and ice sheet change being observed today in Greenland is not unique in the Holocene. The current recession of glaciers in the Scoresby Sund region is exposing sub-fossil vegetation that grew at times when glaciers were smaller than …
Holocene Fire Occurrence And Alluvial Responses At The Leading Edge Of Pinyon–Juniper Migration In The Northern Great Basin, Usa, Kerrie N. Weppner, Jennifer L. Pierce, Julio L. Betancourt
Holocene Fire Occurrence And Alluvial Responses At The Leading Edge Of Pinyon–Juniper Migration In The Northern Great Basin, Usa, Kerrie N. Weppner, Jennifer L. Pierce, Julio L. Betancourt
Geosciences Faculty Publications and Presentations
Fire and vegetation records at the City of Rocks National Reserve (CIRO), south-central Idaho, display the interaction of changing climate, fire and vegetation along the migrating front of single-leaf pinyon (Pinus monophylla) and Utah juniper (Juniperus osteosperma). Radiocarbon dating of alluvial charcoal reconstructed local fire occurrence and geomorphic response, and fossil woodrat (Neotoma) middens revealed pinyon and juniper arrivals. Fire peaks occurred ~10,700–9500, 7200–6700, 2400–2000, 850–700, and 550–400 cal yr BP, whereas ~9500–7200, 6700–4700 and ~1500–1000 cal yr BP are fire-free. Wetter climates and denser vegetation fueled episodic fires and debris flows during the …
A Middle To Late Holocene Record Of Arroyo Cut-Fill Events In Kitchen Corral Wash, Southern Utah, William M. Huff
A Middle To Late Holocene Record Of Arroyo Cut-Fill Events In Kitchen Corral Wash, Southern Utah, William M. Huff
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Arroyos are steeply entrenched channels that form by incision into weakly consolidated valley-fill alluvium. This study attempts to offers clues into the processes behind their formation by dating arroyo sediments using luminescence and radiocarbon techniques. The importance of understanding arroyo formation is due to a possible linkage with decadal to centennial-scale climate fluctuations. In the 1800s and early 1900s, many of the shallow, perennial streams throughout southern Utah that used for a variety of agricultural and domestic uses were incised up to ~30 m into their alluvium by frequent and high-magnitude flood events. The economical and ecological effects of these …
7700 Years Of Holocene Climatic Variability In Sermilik Valley, Southeast Greenland Inferred From Lake Sediments, Samuel H. Davin
7700 Years Of Holocene Climatic Variability In Sermilik Valley, Southeast Greenland Inferred From Lake Sediments, Samuel H. Davin
Masters Theses 1911 - February 2014
During the latter half of the 20th century until present day there has been an unprecedented rise in global annual mean temperatures accompanied by rising sea levels and a decrease in Northern Hemisphere snow cover, which if it continues will lead to widespread disruption of climate patterns, ecosystems, and present-day landscapes. It is therefore of critical importance to establish an expanded network of paleoclimate records across the globe in order to better assesses how the global climate system has changed in the past, that we may create a metric by which to address modern change. Herein is presented a7,700 …
Biogeochemical Evidence For Hydrologic Change During The Holocene In A Lake Sediment Record From Southeast Greenland, Nicholas L. Balascio, William J. D'Andrea, Raymond S. Bradley, Bianca B. Perren
Biogeochemical Evidence For Hydrologic Change During The Holocene In A Lake Sediment Record From Southeast Greenland, Nicholas L. Balascio, William J. D'Andrea, Raymond S. Bradley, Bianca B. Perren
Raymond S Bradley
Holocene paleoclimate records from Greenland help us understand the response of the Greenland Ice Sheet and regional oceanic and atmospheric circulation systems to natural climate variability in order to place recent changes in a longer-term perspective. Here biogeochemical analysis of a lake sediment core from southeast Greenland is used to define changes in moisture balance and runoff during the Holocene in a catchment near the margin of the Greenland Ice Sheet. A 1.6 m sediment core that spans the last 8.8 ka was recovered from Flower Valley Lake on Ammassalik Island. Magnetic susceptibility, diatoms, bulk biogeochemical properties (TOC, C/N, δ13Corg), …
Loess Origin, Transport, And Deposition Over The Past 10,000 Years, Wrangell-St. Elias National Park, Alaska, Daniel R. Muhs, James R. Budahn, John P. Mcgeehin, E. Arthur Bettis Iii, Gary Skipp, James B. Paces, Elisabeth A. Wheeler
Loess Origin, Transport, And Deposition Over The Past 10,000 Years, Wrangell-St. Elias National Park, Alaska, Daniel R. Muhs, James R. Budahn, John P. Mcgeehin, E. Arthur Bettis Iii, Gary Skipp, James B. Paces, Elisabeth A. Wheeler
United States Geological Survey: Staff Publications
Contemporary glaciogenic dust has not received much attention, because most research has been on glaciogenic dust of the last glacial period or non-glaciogenic dust of the present interglacial period. Nevertheless, dust from modern glaciogenic sources may be important for Fe inputs to primary producers in the ocean. Adjacent to the subarctic Pacific Ocean, we studied a loess section near Chitina, Alaska along the Copper River in Wrangell-St. Elias National Park, where dust has been accumulating over the past ~10,000 years. Mass accumulation rates for the fine-grained (<20 >µm) fraction of this loess section are among the highest reported for the …
Origin Of The Sinai-Negev Erg, Egypt And Israel: Mineralogical And Geochemical Evidence For The Importance Of The Nile And Sea Level History, Daniel R. Muhs, Joel Roskin, Haim Tsoar, Gary Skipp, James Budahn, Amihai Sneh, Naomi Porat, Jean-Daniel Stanley, Itzhak Katra, Dan G. Blumberg
Origin Of The Sinai-Negev Erg, Egypt And Israel: Mineralogical And Geochemical Evidence For The Importance Of The Nile And Sea Level History, Daniel R. Muhs, Joel Roskin, Haim Tsoar, Gary Skipp, James Budahn, Amihai Sneh, Naomi Porat, Jean-Daniel Stanley, Itzhak Katra, Dan G. Blumberg
United States Geological Survey: Staff Publications
The Sinai-Negev erg occupies an area of 13,000 km2 in the deserts of Egypt and Israel. Aeolian sand of this erg has been proposed to be derived from the Nile Delta, but empirical data supporting this view are lacking. An alternative source sediment is sand from the large Wadi El Arish drainage system in central and northern Sinai. Mineralogy of the Negev and Sinai dunes shows that they are high in quartz, with much smaller amounts of K-feldspar and plagioclase. Both Nile Delta sands and Sinai wadi sands, upstream of the dunes, also have high amounts of quartz relative …
A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur
A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur
Antioch University Full-Text Dissertations & Theses
This study investigated a terrestrial climate proxy, phytoliths, as a complimentary approach to documenting the dynamics of present and past vegetation on Sanak Island, the largest island in a small island group in the eastern Aleutian archipelago, and as a new basis by which to interpret Holocene environmental variability in Alaska. A phytolith reference collection was established from 59 selected plant species of maritime tundra belonging to 27 families. The grass species and a sedge species produced abundant phytolith forms whereas the majority of dicotyledons in this study were trace producers of phytoliths. A paleoenvironmental reconstruction from fossil phytoliths recovered …