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.

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.

Mapping “At Risk” Snow in the Pacific Northwest

2006 ◽  
Vol 7 (5) ◽  
pp. 1164-1171 ◽  
Author(s):  
Anne W. Nolin ◽  
Christopher Daly
Keyword(s):  
At Risk ◽  
Snow Cover ◽  
Pacific Northwest ◽  
Climate Warming ◽  
The United States ◽  
Cold Climate ◽  
Temperature Threshold ◽  
Precipitation Regime ◽  
The Pacific ◽  
Northwest Region

Abstract One of the most visible and widely felt impacts of climate warming is the change (mostly loss) of low-elevation snow cover in the midlatitudes. Snow cover that accumulates at temperatures close to the ice-water phase transition is at greater risk to climate warming than cold climate snowpacks because it affects both precipitation phase and ablation rates. This study maps areas in the Pacific Northwest region of the United States that are potentially at risk of converting from a snow-dominated to a rain-dominated winter precipitation regime, under a climate-warming scenario. A data-driven, climatological approach of snow cover classification is used to reveal these “at risk” snow zones and also to examine the relative frequency of warm winters for the region. For a rain versus snow temperature threshold of 0°C the at-risk snow class covers an area of about 9200 km2 in the Pacific Northwest region and represents approximately 6.5 km3 of water. Many areas of the Pacific Northwest would see an increase in the number of warm winters, but the impacts would likely be concentrated in the Cascade and Olympic Ranges. A number of lower-elevation ski areas could experience negative impacts because of the shift from winter snows to winter rains. The results of this study point to the potential for using existing datasets to better understand the potential impacts of climate warming.

Wintertime Extreme Precipitation Events along the Pacific Northwest Coast: Climatology and Synoptic Evolution

2012 ◽  
Vol 140 (7) ◽  
pp. 2021-2043 ◽  
Author(s):  
Michael D. Warner ◽  
Clifford F. Mass ◽  
Eric P. Salathé
Keyword(s):  
Pacific Northwest ◽  
Extreme Precipitation ◽  
Precipitable Water ◽  
Small Subset ◽  
Climatic Data ◽  
Central Pacific ◽  
Extreme Precipitation Events ◽  
The Pacific ◽  
Upper Level ◽  
Precipitation Events

Abstract Extreme precipitation events impact the Pacific Northwest during winter months, causing flooding, landslides, extensive property damage, and loss of life. Outstanding questions about such events include whether there are a range of associated synoptic evolutions, whether such evolutions vary along the coast, and the associated rainfall duration and variability. To answer these questions, this study uses 60 years of National Climatic Data Center (NCDC) daily precipitation observations to identify the top 50 events in two-day precipitation at six coastal stations from northern California to northwest Washington. NCEP–NCAR reanalysis data were used to construct synoptic composite evolutions of these events for each coastal location. Most regional flooding events are associated with precipitation periods of 24 h or less, and two-day precipitation totals identify nearly all major events. Precipitation areas of major events are generally narrow, roughly 200 km in width, and most are associated with atmospheric rivers. Composite evolutions indicate negative anomalies in sea level pressure and upper-level height in the central Pacific, high pressure anomalies over the southwest United States, large positive 850-hPa temperature anomalies along the coast and offshore, and enhanced precipitable water and integrated water vapor fluxes over southwest to northeast swaths. A small subset of extreme precipitation events over the southern portion of the domain is associated with a very different synoptic evolution: a sharp trough in northwesterly flow and post-cold-frontal convection. High precipitable water values are more frequent during the summer, but are not associated with heavy precipitation due to upper-level ridging over the eastern Pacific and weak onshore flow that limit upward vertical velocities.

EVALUATING TWO RAINWATER HARVESTING SYSTEMS IN AN URBAN SETTING IN OREGON'S WILLAMETTE VALLEY

2017 ◽  
Vol 12 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Conner Olsen ◽  
Alexander Kowalewski ◽  
Micah Gould ◽  
John Lambrinos
Keyword(s):  
Pacific Northwest ◽  
Rainwater Harvesting ◽  
Urban Setting ◽  
Alternative Methods ◽  
Annual Precipitation ◽  
Residential Setting ◽  
Willamette Valley ◽  
Advantages And Disadvantages ◽  
The Pacific ◽  
Harvesting Systems

INTRODUCTION The recent trend toward more extreme periods of drought has been a shock to the residents of the Pacific Northwest – many of whom have relied upon heavy wateruse in the summer months in order to make a living (i.e. producers of grass seed and sod, berries, or nursery crops), or to maintain their landscapes at high levels (i.e. certain homeowners, recreational facilities, or commercial properties). Furthermore, population growth has reached the point where even an average year of precipitation has proven insufficient for urbanities that had not previously experienced issues with water scarcity (McDonald et al., 2011). This modern climate scenario has forced people of the Pacific Northwest, and people from all around the world, to rethink their water-use strategies, as the global trend has shifted toward greater sustainability (Tilman, 2001; McDonald et al., 2011). One potential mitigation strategy for cool-humid regions, such as Oregon's Willamette Valley, is to utilize rainwater-harvesting systems to alleviate freshwater demand (Kinkade-Levario, 2007). Rainwater harvesting is a logical choice for this climate zone because the average annual precipitation (42.7-in for Corvallis, OR) is sufficient for the majority of its crop production, however, this precipitation occurs almost exclusively in a nine-month period spanning from fall to spring (US Climate Data, 1981–2010). Although annual precipitation is adequate, irrigation is still required for at least three months of every year. This study considered rainwater harvesting to be ideally suited for the cool-humid Willamette Valley; the excess rainfall in the wet season that could be stored for use in the summer months, thus decreasing demand for municipal water by an equivalent amount. It should be stated that rainwater harvesting is not a novel idea; there have been studies dating back to the 1980's and earlier that have shown significant watersavings when retrofitting homes with new features like rainwater-harvesting systems (Boers et al., 1982, Karpisack et al., 1990). Even before that, golf courses, sporting complexes, and industrial sites alike were making use of this strategy. However, their methods typically consisted of catching rainwater via surface runoff and storing it in retention ponds (Ferguson, 1998), which is a strategy that is less applicable to the small-acreage homeowner who wants to irrigate their property without having to turn half of their backyard into a pond. Fortunately, there are alternative methods of rainwater harvesting that make a lot more sense in a residential setting, where irrigated land is small in relation to the roof-area for which rain can be easily harvested. This study documents the construction of two distinct rainwater-harvesting systems (an aboveground cistern and a belowground AQUABLOX™ matrix storage system), and gives insight into their advantages and disadvantages.

The Church of England in the Old Oregon Country

1953 ◽  
Vol 22 (3) ◽  
pp. 219-226
Author(s):  
Thomas E. Jessett
Keyword(s):  
Pacific Northwest ◽  
Church Of England ◽  
Nez Perce ◽  
Willamette Valley ◽  
Christian Missions ◽  
Foreign Missions ◽  
Methodist Church ◽  
Inland Empire ◽  
The Pacific ◽  
Eastern Washington

Most historians of the Pacific Northwest attribute the beginning of Christian missions in the old Oregon country to the appearance at St. Louis, Missouri, in the fall of 1831 of four Nez Perce Indians. According to Protestant sources these Indians were seeking the “Book of Life;” according to Roman Catholics they sought the “Blackrobes,” as the Jesuit missionaries were known. Some modern historians, unable to account for the Indians' interest in Christianity, have even asserted that they had no religious interest at all. The publicity given this event caused the Methodist Church to send out the Reverend Jason Lee in 1834, and the American Board of Commissioners for Foreign Missions to send out the Reverend Samuel Parker in 1835. As a result of these exploratory trips the Methodists established themselves in the Willamette Valley and the American Board sent Marcus Whitman, Henry Spalding and W. H. Gray in 1836 and Cushing Eells, Elkanah Walker and A. B. Smith in 1838 into the area of eastern Washington and Idaho now called the Inland Empire. The Roman Catholic priests, Fathers DeMers and Blanchet, arrived at Fort Vancouver in the fall of 1838.

scholarly journals Perennial Wheat Germ Plasm Lines Resistant to Eyespot, Cephalosporium Stripe, and Wheat Streak Mosaic

Plant Disease ◽  
2002 ◽  
Vol 86 (9) ◽  
pp. 1043-1048 ◽  
Author(s):  
C. M. Cox ◽  
T. D. Murray ◽  
S. S. Jones
Keyword(s):  
Pacific Northwest ◽  
Wheat Germ ◽  
Germ Plasm ◽  
Cropping System ◽  
Sources Of Resistance ◽  
The Pacific ◽  
Perennial Wheat ◽  
Eastern Washington ◽  
Cephalosporium Gramineum ◽  
Wheat Lines

A perennial wheat cropping system on the Palouse Prairie of eastern Washington may provide an alternative to the Federal Conservation Reserve Program and reduce soil erosion while providing a harvestable crop for growers. Twenty-four perennial wheat germ plasm lines resulting from crosses between wheat and wheatgrass were evaluated under controlled environment conditions for resistance to Wheat streak mosaic virus (WSMV), Cephalosporium gramineum, and Tapesia yallundae (anamorph Pseudocercosporella herpotrichoides var. herpotrichoides). Perennial wheat lines SS452, SS103, SS237, MT-2, and PI 550713 were resistant to all three pathogens. Eight lines (33%) were resistant to WSMV at 21°C and 25°C; AT3425 was resistant to WSMV at 21°C but not at 25°C. Thirteen lines (54%) were highly to moderately resistant to C. gramineum. Thirteen lines (54%) were resistant to T. yallundae in each experiment, but the reactions of four lines differed between experiments. The wheatgrasses Thinopyrum intermedium (PI 264770) and Thinopyrum ponticum (PI 206624) are reported as new sources of resistance to T. yallundae. Perennial wheat must have resistance to these diseases in order to be feasible as a crop in the Pacific Northwest.

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