GLACIER CHANGE ON MOUNT RAINIER IN THE CONTEXT OF OTHER VOLCANOES IN THE CASCADE RANGE OF THE PACIFIC NORTHWEST

2017 ◽  
Author(s):  
Andrew G. Fountain ◽  
◽  
Bryce Glenn ◽  
Hassan Basagic
Keyword(s):  
Pacific Northwest ◽  
Cascade Range ◽  
Glacier Change ◽  
The Pacific ◽  
Mount Rainier

Geochemical and Petrological Characterization of Ash Samples from Cascade Range Volcanoes

1971 ◽  
Vol 1 (2) ◽  
pp. 261-282 ◽  
Author(s):  
Keith Randle ◽  
Gordon G. Goles ◽  
Laurence R. Kittleman
Keyword(s):  
Pacific Northwest ◽  
Volcanic Ash ◽  
Cascade Range ◽  
Crystalline Material ◽  
Refractive Indices ◽  
Crystalline Materials ◽  
The Pacific ◽  
Volcanic Ashes ◽  
Different Sources

Twenty-nine samples of volcanic ash from the Pacific Northwest were analyzed by instrumental neutron activation techniques, with the aim of distinguishing among ashes from different sources. Preliminary results of petrographic studies of 42 ash or pumice samples are also reported. Geochemical characteristics of Mazama ash are defined, and problems induced by winnowing of crystalline material during transport and by weathering are discussed. Contents of La, Th, and Co, and La/Yb ratios are shown to be good discriminants. Data on refractive indices and on proportions of crystalline materials also aid in distinguishing among the various volcanic ashes studied. Ash and pumice found in archaeological contexts at Fort Rock Cave, Paisley Cave, Wildcat Canyon, and Hobo Cave are all from Mount Mazama, presumably from the culminating cruption of 7000 years ago.

Altitudinal differentiation between adjacent populations of a ground beetle, Elaphrus americanus Dejean (Coleoptera: Carabidae: Elaphrini)

1982 ◽  
Vol 60 (8) ◽  
pp. 1930-1939
Author(s):  
Henry Frania
Keyword(s):  
Pacific Northwest ◽  
Temperate Forest ◽  
Ground Beetle ◽  
Aldehyde Oxidase ◽  
Body Colour ◽  
Forest Sites ◽  
The Pacific ◽  
Mount Rainier ◽  
Disjunct Populations ◽  
Mount Adams

Samples of Elaphrus americanus from five mountains in the Pacific Northwest were compared for variation in two enzymes (an esterase and an aldehyde oxidase) and a body colour polymorphism. There were significant differences in all three characters between subalpine parkland and temperate forest samples from Mount Rainier and Mount Baker (Washington) and Tusk Mountain (British Columbia). There were no differences between subalpine and temperate forest samples from Mount Adams (Washington) and Mount Hood (Oregon). Subalpine parkland samples from Baker differed from Tusk parkland samples in one character and from Rainier parkland samples in two characters. Differences between forest samples were slight. Large differences over short distances were not expected because dispersal between sites in forest areas is frequent. Parkland populations on Rainier, Baker, and Tusk mountains may be reproductively isolated from adjacent forest populations and could constitute disjunct populations of a sibling species that was widespread in the Pleistocene. Alternatively, subalpine parkland and forest populations may not be reproductively isolated from one another and differences between them are being maintained by selection. Parkland populations on one or more mountains may have diverged independently of the others. Beetles found in parkland areas on Hood and Adams mountains probably dispersed from forest sites.

Postglacial Vegetation and Climate of the Cascade Range, Central Oregon

1995 ◽  
Vol 43 (3) ◽  
pp. 370-381 ◽  
Author(s):  
Debra S. Sea ◽  
Cathy Whitlock
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Climatic Conditions ◽  
Cascade Range ◽  
Pollen Record ◽  
Climate History ◽  
Vegetational Change ◽  
The Pacific ◽  
Closed Forest ◽  
Vegetation And Climate

AbstractPollen data from two sites provide information on the postglacial vegetation and climate history of the Cascade Range. Indian Prairie in the western Cascade Range was colonized by subalpine forests of Pinus, Picea, and Tsuga and open meadows prior to ca. 12,400 14C yr B.P. The treeline lay 500 to 1000 m below its modern elevation and conditions were cooler than at present. From ca. 12,400 to ca. 9950 14C yr B.P. Abies became important and the forest resembled that presently found at middle elevations in the western Cascade Range. The pollen record implies a rise in treeline and warmer conditions than before. From ca. 10,000 to 4000-4500 14C yr B.P., conditions that were warmer and effectively drier than today led to the establishment of a closed forest composed of Pseudotsuga, Abies, and, at lower elevations, Quercus and Corylus. During this period, Gold Lake Bog in the High Cascades was surrounded by closed forest of Pinus and Abies. The early-Holocene pollen assemblages at both Indian Prairie and Gold Lake Bog lack modern analogues, and it is likely that greater-than-present summer radiation fostered unique climatic conditions and vegetation associations at middle and high elevations. In the late Holocene, beginning ca. 4000-4500 14C yr B.P., cooler and more humid conditions prevailed and the modern vegetation was established. A comparison of these sites with others in the Pacific Northwest suggests that major patterns of vegetational change at individual sites were a response to large-scale changes in the climate system that affected the entire region.

Late-Glacial Vegetation and Climate Change in Western Oregon

1998 ◽  
Vol 49 (3) ◽  
pp. 287-298 ◽  
Author(s):  
Laurie D. Grigg ◽  
Cathy Whitlock
Keyword(s):  
Pacific Northwest ◽  
Younger Dryas ◽  
Late Glacial ◽  
Warming Trend ◽  
Cascade Range ◽  
Subalpine Forest ◽  
Coast Range ◽  
The Pacific ◽  
Dry Conditions ◽  
Vegetation And Climate

Pollen records from two sites in western Oregon provide information on late-glacial variations in vegetation and climate and on the extent and character of Younger Dryas cooling in the Pacific Northwest. A subalpine forest was present at Little Lake, central Coast Range, between 15,700 and 14,850 cal yr B.P. A warm period between 14,850 and 14,500 cal yr B.P. is suggested by an increase in Pseudotsuga pollen and charcoal. The recurrence of subalpine forest at 14,500 cal yr B.P. implies a return to cool conditions. Another warming trend is evidenced by the reestablishment of Pseudotsuga forest at 14,250 cal yr B.P. Increased haploxylon Pinus pollen between 12,400 and 11,000 cal yr B.P. indicates cooler winters than before. After 11,000 cal yr B.P. warm dry conditions are implied by the expansion of Pseudotsuga. A subalpine parkland occupied Gordon Lake, western Cascade Range, until 14,500 cal yr B.P., when it was replaced during a warming trend by a montane forest. A rise in Pinuspollen from 12,800 to 11,000 cal yr B.P. suggests increased summer aridity. Pseudotsuga dominated the vegetation after 11,000 cal yr B.P. Other records from the Pacific Northwest show an expansion of Pinus from ca. 13,000 to 11,000 cal yr B.P. This expansion may be a response either to submillennial climate changes of Younger Dryas age or to millennial-scale climatic variations.

Anthocoridae of the Pacific Northwest with Notes on Distributions, Life Histories, and Habits (Heteroptera)

1962 ◽  
Vol 94 (12) ◽  
pp. 1325-1334 ◽  
Author(s):  
N. H. Anderson
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Life Histories ◽  
Common Species ◽  
Cascade Range ◽  
Museum Collections ◽  
Willamette Valley ◽  
The Pacific ◽  
The Family ◽  
Private Collections

This paper is an account of the distributions of the Anthocoridae of the Pacific Northwest (British Columbia, Washington, Oregon, and Idaho), with notes on the life histories of the more common species. It brings together the published and unpublished data on the family in that area. Seven species listed were previously unrecorded there and five others are new species recently described (Kelton and Anderson, 1962). In 1956 and 1957 intensive collecting was done in southern British Columbia and some material was collected in the Willamette Valley and east of the Cascade Range in Oregon. Specimens were examined in the important museum collections of the area and in some private collections.

Paleobotanical evidence for the post-Miocene uplift of the Cascade Range

2014 ◽  
Vol 51 (8) ◽  
pp. 809-824 ◽  
Author(s):  
George E. Mustoe ◽  
Estella B. Leopold
Keyword(s):  
Pacific Northwest ◽  
Late Miocene ◽  
Sharp Decrease ◽  
Cascade Range ◽  
Annual Precipitation ◽  
Climatic Data ◽  
Similarity Coefficients ◽  
Precipitation Regime ◽  
The Pacific ◽  
Eastern Washington

Five Neogene floras in southern Washington and northwest Oregon indicate that the uplift of the Cascade Range occurred after ∼8–6 Ma. Miocene floras west of the range (Wilkes and Faraday floras) resemble paleofloras of correlative age to the east (Rattlesnake Hills, Palouse Falls, and lower Ringold). The statistical similarity of Miocene floras east and west of the Cascade Range axis demonstrates that a similar mesic, warm climate across the Pacific Northwest existed during the Middle and Late Miocene. These floras represent mixed hardwood–conifer forests that commonly contained Taxodium (bald cypress) and other mesophytic taxa. Based on Jaccard similarity coefficients calibrated with climatic data from modern plant communities, these paleofloras indicate a climate that was summer–wet, unlike that of the Pacific Northwest today. The annual precipitation was >100 cm, and the estimated mean annual temperatures of the fossil sites were 12–13 °C. The Miocene floras indicate that the development of a Cascade rain shadow in eastern Washington did not develop until after the deposition of the lower Ringold Formation in eastern Washington. That conclusion is reinforced by a well-documented climate and sediment sequence in the Snake River Valley, Idaho. There, well-dated pollen sections record a sharp decrease (by ∼30%–50%) in the annual precipitation regime after the Late Miocene Banbury Basalt and Poison Creek formations and before ∼3.4 Ma. The existence of extensive late Ringold sediments uplifted on the north side of Saddle Mountain indicates that the structural lifting of the Cascade Range had begun by 3.1 Ma (Pliocene). These data all suggest that the lifting of the Cascades occurred after Miocene time, and that the Cascade rain shadow developed during the Pliocene.

Four centuries of soil carbon and nitrogen change after stand-replacing fire in a forest landscape in the western Cascade Range of Oregon

2008 ◽  
Vol 38 (9) ◽  
pp. 2455-2464 ◽  
Author(s):  
T. W. Giesen ◽  
S. S. Perakis ◽  
K. Cromack
Keyword(s):  
Pacific Northwest ◽  
Forest Floor ◽  
Mineral Soil ◽  
Douglas Fir ◽  
Cascade Range ◽  
Carbon And Nitrogen ◽  
The Pacific ◽  
C And N ◽  
Mineral Soils

Episodic stand-replacing wildfire is a significant disturbance in mesic and moist Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) forests of the Pacific Northwest. We studied 24 forest stands with known fire histories in the western Cascade Range in Oregon to evaluate long-term impacts of stand-replacing wildfire on carbon (C) and nitrogen (N) pools and dynamics within the forest floor (FF, Oe and Oa horizons) and the mineral soil (0–10 cm). Twelve of our stands burned approximately 150 years ago (“young”), and the other 12 burned approximately 550 years ago (“old”). Forest floor mean C and N pools were significantly greater in old stands than young stands (N pools: 1823 ± 132 kg·ha–1vs. 1450 ± 98 kg·ha–1; C pools: 62 980 ± 5403 kg·ha–1vs. 49 032 ± 2965 kg·ha–1, mean ± SE) as a result of significant differences in FF mass. Forest floor C and N concentrations and C/N ratios did not differ by time since fire, yet potential N mineralization rates were significantly higher in FF of old sites. Old and young mineral soils did not differ significantly in pools, concentrations, C/N ratios, or cycling rates. Our results suggest that C and N are sequestered in FF of Pacific Northwest Douglas-fir forests over long (∼400 year) intervals, but that shorter fire return intervals may prevent that accumulation.

Sign in / Sign up

Export Citation Format

Share Document