Aggregations of Sharptail Snakes (Contia tenuis) on the East Slope of the Cascade Range in Washington State

1996 ◽  
Vol 77 (2) ◽  
pp. 47 ◽  
Author(s):  
William P. Leonard ◽  
David M. Darda ◽  
Kelly R. McAllister
2006 ◽  
Vol 65 (1) ◽  
pp. 96-107 ◽  
Author(s):  
Sara Gran Mitchell ◽  
David R. Montgomery

AbstractAnalysis of climatic and topographic evidence from the Cascade Range of Washington State indicates that glacial erosion limits the height and controls the morphology of this range. Glacial erosion linked to long-term spatial gradients in the ELA created a tilted, planar zone of 373 cirques across the central part of the range; peaks and ridges now rise ≤600 m above this zone. Hypsometric analysis of the region shows that the proportion of land area above the cirques drops sharply, and mean slopes >30° indicate that the areas above the cirques may be at or near threshold steepness. The mean plus 1σ relief of individual cirque basins (570 m) corresponds to the ∼600-m envelope above which peaks rarely rise. The summit altitudes are set by a combination of higher rates of glacial and paraglacial erosion above the ELA and enhanced hillslope processes due to the creation of steep topography. On the high-precipitation western flank of the Cascades, the dominance of glacial and hillslope erosion at altitudes at and above the ELA may explain the lack of a correspondence between stream-power erosion models and measured exhumation rates from apatite (U-Th/He) thermochronometry.


2010 ◽  
Vol 73 (2) ◽  
pp. 313-323 ◽  
Author(s):  
Jon L. Riedel ◽  
John J. Clague ◽  
Brent C. Ward

Twenty-two new radiocarbon ages from Skagit valley provide a detailed chronology of alpine glaciation during the Evans Creek stade of the Fraser Glaciation (early marine oxygen isotope stage (MIS) 2) in the Cascade Range, Washington State. Sediments at sites near Concrete, Washington, record two advances of the Baker valley glacier between ca. 30.3 and 19.5 cal ka BP, with an intervening period of glacier recession about 24.9 cal ka BP. The Baker valley glacier dammed lower Skagit valley, creating glacial Lake Concrete, which discharged around the ice dam along Finney Creek, or south into the Sauk valley. Sediments along the shores of Ross Lake in upper Skagit valley accumulated in glacial Lake Skymo after ca. 28.7 cal ka BP behind a glacier flowing out of Big Beaver valley. Horizontally laminated silt and bedded sand and gravel up to 20 m thick record as much as 8000 yr of deposition in these glacially dammed lakes. The data indicate that alpine glaciers in Skagit valley were far less extensive than previously thought. Alpine glaciers remained in advanced positions for much of the Evans Creek stade, which may have ended as early as 20.8 cal ka BP.


1989 ◽  
Vol 13 ◽  
pp. 51-55 ◽  
Author(s):  
Carolyn L. Driedger ◽  
Andrew G. Fountain

During the twentieth century, glacial outburst floods have been the most destructive natural events on Mount Rainier, a stratovolcano in the Cascade Range in Washington State, U.S.A. In the period between 1930 and 1980 numerous floods were reported from five glaciers on the mountain, most of which flowed from Nisqually, Kautz, or South Tahoma Glaciers on its southern flank. Such floods threaten lives and property because they occur without warning and quickly mobilize the loose volcanic debris into debris flows. A monitoring program was begun in 1987 which was designed to measure the dimensions and timing of outburst floods, but this has been unsuccessful because no floods have yet occurred on the monitored streams. Four floods did burst from South Tahoma Glacier that was unmonitored, but in spite of this they have been useful in providing evidence of flood storage and release mechanisms. All flood volumes were found to be of approximately similar orders of magnitude, of 1 × 105 m3 of water, indicating that all floods probably had similar mechanisms for storage and release of water. Hydraulic pressure considerations indicate that such a large volume of flood water would be stored at the bed of the glacier rather than in isolated englacial cavities. The stepped bedrock terrain provides an ideal setting for the formation of subglacial cavities capable of storing the volumes of flood water noted.


2006 ◽  
Vol 306 (9) ◽  
pp. 736-768 ◽  
Author(s):  
S. G. Mitchell ◽  
D. R. Montgomery

1989 ◽  
Vol 13 ◽  
pp. 51-55 ◽  
Author(s):  
Carolyn L. Driedger ◽  
Andrew G. Fountain

During the twentieth century, glacial outburst floods have been the most destructive natural events on Mount Rainier, a stratovolcano in the Cascade Range in Washington State, U.S.A. In the period between 1930 and 1980 numerous floods were reported from five glaciers on the mountain, most of which flowed from Nisqually, Kautz, or South Tahoma Glaciers on its southern flank. Such floods threaten lives and property because they occur without warning and quickly mobilize the loose volcanic debris into debris flows.A monitoring program was begun in 1987 which was designed to measure the dimensions and timing of outburst floods, but this has been unsuccessful because no floods have yet occurred on the monitored streams. Four floods did burst from South Tahoma Glacier that was unmonitored, but in spite of this they have been useful in providing evidence of flood storage and release mechanisms. All flood volumes were found to be of approximately similar orders of magnitude, of 1 × 105 m3 of water, indicating that all floods probably had similar mechanisms for storage and release of water. Hydraulic pressure considerations indicate that such a large volume of flood water would be stored at the bed of the glacier rather than in isolated englacial cavities. The stepped bedrock terrain provides an ideal setting for the formation of subglacial cavities capable of storing the volumes of flood water noted.


2014 ◽  
Vol 146 (4) ◽  
pp. 415-428 ◽  
Author(s):  
Eugene R. Miliczky ◽  
David R. Horton ◽  
Eric LaGasa

AbstractThe eastern foothills of the Cascade Range in Washington State, United States of America are west of the State's major fruit-producing region. Alders (Alnus Hill (Betulaceae)), an important floristic component of riparian communities in the Cascade Range foothills, were surveyed for leafrolling caterpillars (Lepidoptera: Tortricidae) that might serve as alternate hosts for parasitoids of orchard pest leafrollers, particularly the nonnative wasp Colpoclypeus florus (Walker) (Hymenoptera: Eulophidae). Tortricid leafrollers were abundant on alder, but reared parasitoids did not include C. florus. Survey results also revealed that rolled leaves were secondarily colonised by a wide variety of predatory and phytophagous arthropods. Rolled leaves were almost 10-fold more likely to be occupied by predatory arthropods than adjacent, roll-free leaves. Phytophagous thrips and mites showed a similar preference for rolled leaves. The most abundant predaceous arthropods in the leafrolls were Anthocoris antevolens White (Hemiptera: Anthocoridae), found in 4.4% of leafrolls, and the spider Clubiona pacifica Banks (Araneae: Clubionidae), found in 8.3% of leafrolls. Both species, and several other predatory insect and spider species found in the rolled leaves, also occur in eastern Washington orchards where they contribute to biological control. Because of its frequent colonisation by beneficial arthropods, alder may prove useful in conservation biological control programs.


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