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"Thunderbird and Whale" is an indigenous myth belonging to the mythological traditions of a number of tribes from the American Pacific Northwest.
California is a U.S. state on the western coast of North America. Covering an area of 163,696 sq mi (423,970 km2), California is among the most geographically diverse states. The Sierra Nevada, the fertile farmlands of the Central Valley, and the arid Mojave Desert of the south are some of the major geographic features of this U.S. state. It is home to some of the world's most exceptional trees: the tallest, most massive, and oldest. It is also home to both the highest and lowest points in the 48 contiguous states. The state is generally divided into Northern and Southern California, although the boundary between the two is not well defined. San Francisco is decidedly a Northern California city and Los Angeles likewise a Southern California one, but areas in between do not often share their confidence in geographic identity. The US Geological Survey defines the geographic center of the state at a point near North Fork, California.
The San Andreas Fault is a continental right-lateral strike-slip transform fault that extends roughly 1,200 kilometers (750 mi) through the Californias. It forms the tectonic boundary between the Pacific Plate and the North American Plate. Traditionally, for scientific purposes, the fault has been classified into three main segments, each with different characteristics and a different degree of earthquake risk. The average slip rate along the entire fault ranges from 20 to 35 mm per year.
The 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Friday earthquake, occurred at 5:36 PM AKST on Good Friday, March 27. Across south-central Alaska, ground fissures, collapsing structures, and tsunamis resulting from the earthquake caused about 131 deaths.
The 1960 Valdivia earthquake and tsunami or the Great Chilean earthquake on 22 May 1960 was the most powerful earthquake ever recorded. Various studies have placed it at 9.4–9.6 on the moment magnitude scale. It occurred in the afternoon, and lasted for approximately 10 minutes. The resulting tsunamis affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia, and the Aleutian Islands.
The Missoula floods were cataclysmic glacial lake outburst floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age. These floods were the result of periodic sudden ruptures of the ice dam on the Clark Fork River that created Glacial Lake Missoula. After each ice dam rupture, the waters of the lake would rush down the Clark Fork and the Columbia River, flooding much of eastern Washington and the Willamette Valley in western Oregon. After the lake drained, the ice would reform, creating Glacial Lake Missoula again.
The Juan de Fuca Plate is a small tectonic plate (microplate) generated from the Juan de Fuca Ridge that is subducting beneath the northerly portion of the western side of the North American Plate at the Cascadia subduction zone. It is named after the explorer of the same name. One of the smallest of Earth's tectonic plates, the Juan de Fuca Plate is a remnant part of the once-vast Farallon Plate, which is now largely subducted underneath the North American Plate.
The 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26, 1700, with an estimated moment magnitude of 8.7–9.2. The megathrust earthquake involved the Juan de Fuca Plate from mid-Vancouver Island, south along the Pacific Northwest coast as far as northern California. The length of the fault rupture was about 1,000 kilometers, with an average slip of 20 meters (66 ft).
The Seattle Fault is a zone of multiple shallow east–west thrust faults that cross the Puget Sound Lowland and through Seattle in the vicinity of Interstate Highway 90. The Seattle Fault was first recognized as a significant seismic hazard in 1992, when a set of reports showed that about 1,100 years ago it was the scene of a major earthquake of about magnitude 7 – an event that entered Native American oral legend. Extensive research has since shown the Seattle Fault to be part of a regional system of faults.
The Cascadia subduction zone is a 960 km fault at a convergent plate boundary, about 112-160 km off the Pacific Shore, that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is capable of producing 9.0+ magnitude earthquakes and tsunamis that could reach 30m. The Oregon Department of Emergency Management estimates shaking would last 5-7 minutes along the coast, with strength and intensity decreasing further from the epicenter. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca, and Gorda plates move to the east and slide below the much larger mostly continental North American Plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.
Paleoseismology looks at geologic sediments and rocks, for signs of ancient earthquakes. It is used to supplement seismic monitoring, for the calculation of seismic hazard. Paleoseismology is usually restricted to geologic regimes that have undergone continuous sediment creation for the last few thousand years, such as swamps, lakes, river beds and shorelines.
The Huu-ay-aht First Nations is a First Nations band government based on Pachena Bay about 300 km (190 mi) northwest of Victoria, British Columbia on the west coast of Vancouver Island, in Canada. The traditional territories of the Huu-ay-aht make up the watershed of the Sarita River. The Huu-ay-aht is a member of the Nuu-chah-nulth Tribal Council and is a member of the Maa-nulth Treaty Society. It completed and ratified its community constitution and ratified the Maa-nulth Treaty on 28 July 2007. The Legislative Assembly of British Columbia passed the Maa-nulth First Nations Final Agreement Act on Wednesday, 21 November 2007 and celebrated with the member-nations of the Maa-nulth Treaty Society that evening.
John Joseph Clague PhD FRSC OC is a Canadian authority in Quaternary and environmental earth sciences. He is a professor of earth sciences at Simon Fraser University and an emeritus scientist of the Geological Survey of Canada.
The 1992 Cape Mendocino earthquakes occurred along the Lost Coast of Northern California on April 25 and 26. The three largest events were the M7.2 thrust mainshock that struck near the unincorporated community of Petrolia midday on April 25 and two primary strike-slip aftershocks measuring 6.5 and 6.6 that followed early the next morning. The sequence encompassed both interplate and intraplate activity that was associated with the Mendocino Triple Junction, a complex system of three major faults that converge near Cape Mendocino. The total number of aftershocks that followed the events exceeded 2,000.
The 1898 Mare Island earthquake occurred in Northern California on March 30 at 23:43 local time with a moment magnitude of 5.8–6.4 and a maximum Mercalli intensity of VIII–IX (Severe–Violent). Its area of perceptibility included much of northern and central California and western Nevada. Damage amounted to $350,000 and was most pronounced on Mare Island, a peninsula in northern San Francisco Bay. While relatively strong effects there were attributed to vulnerable buildings, moderate effects elsewhere in the San Francisco Bay Area consisted of damaged or partially collapsed structures, and there were media reports of a small tsunami and mostly mild aftershocks that followed.
Ghost forests are areas of dead trees in former forests, typically in coastal regions where rising sea levels or tectonic shifts have altered the height of a land mass. Forests located near the coast or estuaries may also be at risk of dying through saltwater poisoning, if invading seawater reduces the amount of freshwater that deciduous trees receive for sustenance.
On January 23, 2018, at 00:31 AKST, an earthquake occurred in the Gulf of Alaska near Kodiak Island. The earthquake, measured at 7.9 on the Mw scale, was approximately 280 kilometers (170 mi) southeast of Kodiak and happened at a depth of 25 kilometers (16 mi).
Pachena Bay is located 13 km (8.1 mi) south of Bamfield in Pacific Rim National Park at the southern end of Vancouver Island, British Columbia, Canada. It was the location of a First Nation's village that was destroyed by a tsunami in 1700.
The 1585 Aleutian Islands earthquake is the presumed source of a tsunami along the Sanriku coast of Japan on June 11, 1585, known only from vague historical accounts and oral traditions. The event was initially misdated to 1586, which led to it being associated with the deadly earthquakes in Peru and Japan of that year. The source earthquake was later determined by modern seismological studies to have originated near the Aleutian Islands in the North Pacific Ocean. Paleotsunami evidence from shoreline deposits and coral rocks in Hawaii suggest that the 1585 event was a large megathrust earthquake occurring on the Aleutian subduction zone with a moment magnitude (Mw ) as large as 9.25.
References
- ↑ "Brian F. Atwater". The Franklin Institute. 28 October 2015. Retrieved 24 December 2020.
