Geology topics

Research about California, Washington

Source-linked reports with geographic coverage including California, Washington.

10 recordsLinked to original sources

USGS2026

Can a physics-based fire behavior model predict burn severity and post-fire debris flow hazard?

Post-wildfire flooding and debris flows pose a threat to ecosystems and infrastructure. As the frequency and size of severe wildfires increase, there is a growing need for predictive debris flow hazard modeling in unburned but fire-prone landscapes. However, no crosswalks have been established between physics-based models of fire behavior and the remotely sensed burn severity inputs needed for debris flow modeling. Here, we explore this connection by creating a large ensemble of fire behavior simulations using QUIC-Fire – a fast-running three-dimensional fire model – in basins across five major-disaster wildfires in California and Washington. We then conducted generalized linear mixed modeling (GLMM) and Random Forest modeling to identify QUIC-Fire outputs that best predicted remotely sensed burn severity. We found that the selected linear predictors exhibited weak and unintuitive relationships with soil burn severity and differenced Normalized Burn Ratio. Moreover, model evaluations of GLMMs and Random Forests showed they were poorly predictive of both metrics of remotely sensed burn severity. This suggests that there are barriers to integrating QUIC-Fire into a wildfire-hazards modeling framework, which could include mismatches in scale between fire models and remotely sensing, or simplifications of weather data and fire initiation. Further research is needed to establish connections between the fire physics outputs of QUIC-Fire and post-fire effects to vegetation and soils that are essential for evaluating debris flow hazard.

California, Washington↗

USGS2021

STEPS: Slip time earthquake path simulations applied to the San Andreas and Toe Jam Hill Faults to redefine geologic slip rate uncertainty

Geologic slip rates are a time-averaged measurement of fault displacement calculated over hundreds to million-year time scales and are a primary input for probabilistic seismic hazard analyses, which forecast expected ground shaking in future earthquakes. Despite their utility for seismic hazard calculations, longer-term geologic slip rates represent a time-averaged measure of the tempo of strain release and do not measure variability across earthquake cycles. We have developed a numerical approach called STEPS (Slip Time Earthquake Path Simulations), which is built upon field-based observations and explicitly incorporates realistic variations in displacement per event and variability in the recurrence interval between earthquakes. The STEPS approach, which simulates strain release through time, relies on representing earthquake cycles as stairsteps, rather than straight-line paths, connecting per earthquake time-displacement coordinates. We simulate earthquake histories based on these input constraints using two examples: the Carrizo section of the San Andreas fault and the Toe Jam Hill fault of the Seattle fault zone. We find that modeled slip rate distributions agree with slip rates reported for the sites of interest by the original investigators, while providing a slip rate distribution that reflects the variability of earthquake frequency and displacement. The STEPS approach provides an estimate of fault slip rate uncertainty based on a synthetic suite of plausible time-displacement paths resulting from individual earthquakes, rather than measurement uncertainties associated with offset features. When considering this simulated earthquake behavior between measurements, the uncertainty associated with earthquake paths is greater than that calculated by the long-term rate.

California, Washington↗

USGS2020

Littoral sediment from rivers: Patterns, rates and processes of river mouth morphodynamics

Rivers provide important sediment inputs to many littoral cells, thereby replenishing sand and gravel of beaches around the world. However, there is limited information about the patterns and processes of littoral-grade sediment transfer from rivers into coastal systems. Here I address these information gaps by examining topographic and bathymetric data of river mouths and constructing sediment budgets to characterize time-dependent patterns of onshore, offshore, and alongshore transport. Two river deltas, which differ in their morphology, were used in this study: the Elwha River, Washington, which builds a mixed sediment Gilbert-style delta, and the Santa Clara River, California, which builds a cross-shore dispersed sand delta from hyperpycnal flows. During and after sediment discharge events, both systems exhibited a similar evolution composed of three phases: (i) submarine delta growth during offshore transport of river sediment, (ii) onshore-dominated transport from the submarine delta to a subaerial river mouth berm, and (iii) longshore-dominated transport away from the river mouth following subaerial berm development. Although stage (ii) occurred within days to weeks for the systems studied and was associated with the greatest rates of net erosion and deposition, onshore transport of sediment from submarine deposit to the beach persisted for years following the river discharge event. These morphodynamics were similar to simple equilibrium profile concepts that were modified with an onshore-dominated cross-shore transport rule. Additionally, both study sites revealed that littoral-grade sediment was initially exported to depths beyond the active littoral cell (i.e., below the depth of closure) during the stage (i). Following several years of reworking by coastal processes, bathymetric surveys suggested that 14 and 46% of the original volume of littoral-grade sediment discharged by the Santa Clara and Elwha Rivers, respectively, continued to be below the depth of closure. Combined, this suggests that integration of river sediment into a littoral cell can be a multi-year process and that the full volume of littoral-grade sediment discharged by small rivers may not be integrated into littoral cells because of sand and gravel “losses” to the continental shelf.

California, Washington↗

USGS2008

Genetic diversity among sea otter isolates of Toxoplasma gondii

Sea otters ( Enhydra lutris ) have been reported to become infected with Toxoplasma gondii and at times succumb to clinical disease. Here, we determined genotypes of 39 T. gondii isolates from 37 sea otters in two geographically distant locations (25 from California and 12 from Washington). Six genotypes were identified using 10 PCR-RFLP genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico, and by DNA sequencing of loci SAG1 and GRA6 in 13 isolates. Of these 39 isolates, 13 (33%) were clonal Type II which can be further divided into two groups at the locus Apico. Two of the 39 isolates had Type II alleles at all loci except a Type I allele at locus L358. One isolate had Type II alleles at all loci except the Type I alleles at loci L358 and Apico. One isolate had Type III alleles at all loci except Type II alleles at SAG2 and Apico. Two sea otter isolates had a mixed infection. Twenty-one (54%) isolates had an unique allele at SAG1 locus. Further genotyping or DNA sequence analysis for 18 of these 21 isolates at loci SAG1 and GRA6 revealed that there were two different genotypes, including the previously identified Type X (four isolates) and a new genotype named Type A (14 isolates). The results from this study suggest that the sea otter isolates are genetically diverse.

California, Washington↗

USGS2008

Modest genetic differentiation among North American populations of Sarcocystic neurona may reflect expansion in its geographic range

Sarcocystis neurona is an important cause of neurological disease in horses (equine protozoal myeloencephalitis, EPM) and sea otters in the United States. In addition, EPM-like disease has been diagnosed in several other land and marine mammals. Opossums are its only definitive hosts. Little genetic diversity among isolates of S. neurona from different hosts has been reported. Here, we used 11 microsatellites to characterize S. neurona DNA isolated from natural infections in 22 sea otters (Enhydra lutris) from California and Washington and in 11 raccoons (Procyon lotor) and 1 striped skunk (Mephitis mephitis) from Wisconsin. By jointly analyzing these 34 isolates with 26 isolates previously reported, we determined that geographic barriers may limit S. neurona dispersal and that only a limited subset of possible parasite genotypes may have been introduced to recently established opossum populations. Moreover, our study confirms that diverse intermediate hosts share a common infection source, the opossum (Didelphis virginiana).

California, Washington↗

USGS2007

Protozoal meningoencephalitis in sea otters (Enhydra lutris): A histopathological and immunohistochemical study of naturally occurring cases

Protozoal meningoencephalitis is considered to be an important cause of mortality in the California sea otter ( Enhydra lutris ). Thirty nine of 344 (11.3%) California (CA) and Washington state (WA) sea otters examined from 1985 to 2004 had histopathological evidence of significant protozoal meningoencephalitis. The aetiological agents and histopathological changes associated with these protozoal infections are described. The morphology of the actively multiplicative life stages of the organisms (tachyzoites for Toxoplasma gondii and merozoites for Sarcocystis neurona ) and immunohistochemical labelling were used to identify infection with S. neurona ( n =22, 56.4%), T. gondii ( n =5, 12.8%) or dual infection with both organisms ( n =12, 30.8%). Active S. neurona was present in all dual infections, while most had only the latent form of T. gondii . In S. neurona meningoencephalitis, multifocal to diffuse gliosis was widespread in grey matter and consistently present in the molecular layer of the cerebellum. In T. gondii meningoencephalitis, discrete foci of gliosis and malacia were more widely separated, sometimes incorporated pigment-laden macrophages and mineral, and were found predominantly in the cerebral cortex. Quiescent tissue cysts of T. gondii were considered to be incidental and not a cause of clinical disease and mortality. Protozoal meningoencephalitis was diagnosed more frequently in the expanding population of WA sea otters (10 of 31, 32.3%) than in the declining CA population (29 of 313, 9.3%). Among sea otters with protozoal meningoencephalitis, those that had displayed neurological signs prior to death had active S. neurona encephalitis, supporting the conclusion that S. neurona is the most significant protozoal pathogen in the central nervous system of sea otters.

California, Washington↗

USGS2001

Did you feel it? Community-made earthquake shaking maps

Since the early 1990's, the magnitude and location of an earthquake have been available within minutes on the Internet. Now, as a result of work by the U.S. Geological Survey (USGS) and with the cooperation of various regional seismic networks, people who experience an earthquake can go online and share information about its effects to help create a map of shaking intensities and damage. Such 'Community Internet Intensity Maps' (CIIM's) contribute greatly in quickly assessing the scope of an earthquake emergency, even in areas lacking seismic instruments.

California, Washington↗

USGS1983

Pacific Coast Caspian Terns: Dynamics of an expanding population

Nesting distribution, age-related seasonal movements, survivorship, and mechanisms of population expansion in Pacific Coast Caspian Terns (Sterna caspia) were examined primarily through analysis of 412 recoveries of birds banded as juveniles between 1935 and 1980. Since the beginning of this century, the population has shifted from nesting in numerous small colonies associated with freshwater marshes in interior California and southern Oregon to nesting primarily in large colonies on human-created habitats along the coast. Colonies at Grays Harbor, Washington and San Francisco and San Diego bays, California account for 77% of the current Pacific Coast population (6,000 pairs), which has breeding and wintering areas separate from those of populations east of the continental divide. There also appears to be some segregation on the wintering grounds by birds from the three major colonies within the Pacific population. Age-related seasonal movements in the Pacific population are characterized by (1) a brief period of northward dispersal by newly fledged birds before migrating to the wintering grounds, (2) a residency on the wintering grounds through their second winter, (3) a return to the breeding grounds the third summer, when most birds are thought to prospect breeding sites and some may breed, and (4) attainment of adulthood the fourth summer, with subsequent annual movements between wintering and breeding grounds. The Pacific population has increased 70% since 1960, apparently all by intrinsic growth. Over half (57%) of the fledglings reach their fourth year, and they have a subsequent annual survival rate of 89% and a mean breeding life expectancy of 8.6 yr. An average annual fledging rate of 0.64 young per pair was calculated as necessary to have provided the observed growth of the population during its recent expansion. Growth of some of the individual colonies, however, particularly those in Washington, could only have resulted from extensive recruitment of birds from other Pacific Coast colonies. Philopatry is low in this population, and the growth of the northern colonies involved recruitment primarily of first-time breeders but also of some older adults. Factors promoting both first-time breeders and older adults to join new and often distant colonies are discussed.

California, Washington↗

USGS1981

Food of the Pacific white-sided dolphin, Lagenorhynchus obliquidens, Dall's porpoise, Phocoenoides dalli, and northern fur seal, Callorhinus ursinus, off California and Washington

Our knowledge of the feeding habits of the Pacific white-sided dolphin, Lagenorhynchus obliquidens , and the Dall's porpoise, Phocoenoides dalli , is based on examination of the stomach contents of stranded animals, animals accidentally taken in commercial fishing gear, those taken in the western Pacific commercial fishery, and animals that died during capture attempts. Of these only a few were normally feeding animals taken at sea, whose stomach contents were thoroughly examined. Fished and squids previously identified from stomachs of dolphins and porpoises by various investigators are listed in Table 1. This paper documents the stomach contents of 44 Pacific white-sided dolphin and 9 Dall's porpoise collected at sea off California and Washington. All animals were collected by the authors during pelagic fur seal studies with the exception of three dolphins which were collected by a staff biologist during whale research voyages off California. Comparisons of stomach contents are made between the Pacific white-sided dolphins, Dall's porpoise, and northern fur seal, Callorhinus ursinus , collected near the same locations and usually on the same day. Mention of the dolphin, porpoise , and seal in this paper refers to the above-named species unless noted otherwise.

California, Washington↗

USGS1970

Thermal features at Volcanoes in the cascade range, as observed by aerial infrared surveys

There have been no substantial changes in the thermal patterns at the summit of Mount Rainier in the period September 1964–September 1966, within the detection limits of the infrared instrumentation. Some differences in radiance are attributed to differences in snow cover. The highest apparent temperature is at a snow-free area on the west flank of the summit cone, several hundred feet below the west crater rim. An anomaly at this site was recorded on both infrared surveys, but no prior reports of thermal activity here have been made by ground parties. Other anomalous thermal zones at the summit are on the northern quadrants of both crater rims. A very small, low-temperature fumarole reported on Mount Adams was not detected, nor were any other thermal manifestations recorded. One anomaly consisting of a close-spaced cluster of thermal spots was detected at The Boot on Mount St. Helens and corresponds to a known fumarole area. The only thermal feature seen on Mount Shasta is near the summit at a thermal spring that has been observed by many climbers. Two anomalies were found on the north flank of Lassen Peak. Thermal activity had not been previously reported at either site, though one is in a known solfatarized area. No ground investigation has been made at the other location. Much of the other thermal activity in the Lassen Peak area is in the northeast quadrant of Brokeoff Caldera. Most of these features are well documented in the literature; others not previously described are in fairly accessible areas and doubtless result from springs and fumaroles related to Brokeoff Caldera.

California, Washington↗