The primary goal of this research project is to quantitatively measure the temporal scales of hyporheic exchange along a stream network. Our goal is to examine how hyporheic exchange varies with increasing stream size. Many previous studies focus on single stream reaches or on several reaches of similar sized streams,...
Sediment storage in and release from the Granite Creek catchment over Holocene timescales is modulated by the fluctuations of Tana Glacier, which periodically blocks the outlet of Granite Creek. Little Ice Age expansion from 1500-1900 AD is suggested by lichenometric ages of alpine glacial moraines within Granite Creek valley. Trimlines...
The Yanacocha Mining District in northern Perú is considered the largest group of
high-sulfidation style epithermal gold deposits in the world. District-scale geologic mapping coupled with detailed 40Ar/39Ar geochronology, geochemistry and petrography establish the volcanic history of the area and analyze the temporal and spatial evolution of volcanism, hypogene advanced...
Mount Shasta, the southernmost stratovolcano in the Cascade Range (41.4°N) has
frequently produced lahars of various magnitudes during the last 10,000 yr. These include
large flows of eruptive origin, reaching more than 40km from the summit, and studies have
shown that at least 70 debris flows of noneruptive origin have...
The climatic and tectonic framework of the St. Elias orogen makes it an excellent place to study the interactions between tectonic processes such as deformation and erosive processes, in particular glacial erosion. One type of link between these processes, proposed by numerical models of orogenic development, is an effect of...
The Central Oregon High Cascade Range is an anomalously mafic segment of the Cascade Arc due to ongoing intra-arc extension, which allows most magmas to traverse the crust without stalling and evolving to more evolved compositions. North Sister, a composite volcano in this arc segment, has produced a seemingly monotonous...
The objective of this study was to examine vegetation and vegetation change in Eritrea over a period from the mid 1980s to 2002 using satellite remote sensing, and relate observed changes to the recent history of drought and war in the region. Specific objectives were (1) to examine vegetation change...