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Glaciology

Portland State University

Glaciers -- Climatic factors

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Glacier Recession And The Response Of Summer Streamflow In The Pacific Northwest United States, 1960–2099, Chris Frans, Erkan Istanbulluoglu, Dennis P. Lettenmaier, Andrew G. Fountain, Jon L. Riedel Jan 2018

Glacier Recession And The Response Of Summer Streamflow In The Pacific Northwest United States, 1960–2099, Chris Frans, Erkan Istanbulluoglu, Dennis P. Lettenmaier, Andrew G. Fountain, Jon L. Riedel

Geology Faculty Publications and Presentations

The Pacific Northwest is the most highly glacierized region in the conterminous United States (858 glaciers; 466 km2). These glaciers have displayed ubiquitous patterns of retreat since the 1980s mostly in response to warming air temperatures. Glacier melt provides water for downstream uses including agricultural water supply, hydroelectric power generation, and for ecological systems adapted to cold reliable streamflow. While changes in glacier area have been studied within the region over an extended period of time, the hydrologic consequences of these changes are not well defined. We applied a high‐resolution glacio‐hydrological model to predict glacier mass balance, glacier area, and …


The Geography Of Glaciers And Perennial Snowfields In The American West, Andrew G. Fountain, Bryce Glenn, Hassan J. Basagic Aug 2017

The Geography Of Glaciers And Perennial Snowfields In The American West, Andrew G. Fountain, Bryce Glenn, Hassan J. Basagic

Geology Faculty Publications and Presentations

A comprehensive mid-20th century inventory of glaciers and perennial snowfields (G&PS) was compiled for the American West, west of the 100° meridian. The inventory was derived from U.S. Geological Survey 1:24,000 topographic maps based on aerial photographs acquired during 35 years, 1955–1990, of which the first 20 years or more was a cool period with little glacier change. The mapped features were filtered for those greater than 0.01 km2. Results show that 5036 G&PS (672 km2, 14 km3) populate eight states, of which about 1276 (554 km2, 12 km3) are glaciers. …


Glacier Status And Contribution To Streamflow In The Olympic Mountains, Usa, Jon L. Riedel, Steve Wilson, William Baccus, Michael Larrabee, T.J. Fudge, Andrew G. Fountain Feb 2015

Glacier Status And Contribution To Streamflow In The Olympic Mountains, Usa, Jon L. Riedel, Steve Wilson, William Baccus, Michael Larrabee, T.J. Fudge, Andrew G. Fountain

Geology Faculty Publications and Presentations

The Olympic Peninsula, Washington, USA, currently holds 184 alpine glaciers larger than 0.01 km² and their combined area is 30.2 ± 0.95km². Only four glaciers are >1km² and 120 of the others are -¹ (1900–80) to 0.54 km² a-¹ (1980–2009). Thinning rates on four of the largest glaciers averaged nearly 1ma-¹ from 1987 to 2010, resulting in estimated volume losses of 17–24%. Combined glacial snow, firn and ice melt in the Hoh watershed is in the range 63–79 ± 7 × 106m3, or 9–15% of total May–September streamflow. In the critical August–September …


A Data Set Of Worldwide Glacier Length Fluctuations, Paul W. Leclercq, Johannes Oerlemans, Hassan J. Basagic, Christina Bushueva, A. J. Cook, Raymond Le Bris Jan 2014

A Data Set Of Worldwide Glacier Length Fluctuations, Paul W. Leclercq, Johannes Oerlemans, Hassan J. Basagic, Christina Bushueva, A. J. Cook, Raymond Le Bris

Geology Faculty Publications and Presentations

Glacier fluctuations contribute to variations in sea level and historical glacier length fluctuations are natural indicators of past climate change. To study these subjects, longterm information of glacier change is needed. In this paper we present a data set of global long-term glacier length fluctuations. The data set is a compilation of available information on changes in glacier length worldwide, including both measured and reconstructed glacier length fluctuations. All 471 length series start before 1950 and cover at least four decades. The longest record starts in 1535, but the majority of time series start after 1850. The number of available …


Quantifying Twentieth Century Glacier Change In The Sierra Nevada, California, Hassan J. Basagic Jan 2008

Quantifying Twentieth Century Glacier Change In The Sierra Nevada, California, Hassan J. Basagic

Dissertations and Theses

Numerous small alpine glaciers occupy the high elevation regions of the central and southern Siena Nevada, California. These glaciers change size in response to variations in climate and are therefore important indicators of climate change. An inventory based on USGS topographic maps (l :24,000) revealed 1719 glaciers and perennial snow and ice features for a total area of 39.l5 ±7.52 km2. The number of 'true' glaciers, versus non-moving ice, is estimated to be 118, covering 15.87 ± 1.69 Km2. All glaciers were located on north to northeast aspects, at elevations >3000 m. Historical photographs, geologic evidence, …