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1969 Santa Rosa Earthquakes
At 04:56 and 06:19 UTC on October 2, 1969 (21:56 and 23:19 PDT October 1), a pair of earthquakes of magnitude 5.6 and 5.7, respectively, struck the city of Santa Rosa, California, killing one person and damaging buildings. The maximum felt intensity for the two events was VII (''Very strong'') and VIII (''Severe'') respectively on the Mercalli intensity scale. The $8.35 million cost of the earthquakes went mostly to replace buildings damaged beyond repair. There were at least 200 aftershocks after the initial pair of earthquakes. At the time they were the largest earthquakes to affect the northern San Francisco Bay Area since the 1906 San Francisco earthquake. Tectonic setting The current tectonics of northern California are mainly controlled by the San Andreas Fault system, the zone of dextral strike-slip faulting that accommodates displacement between the North American Plate and the Pacific Plate along this transform boundary. In addition to the San Andreas Fault itself there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Rosa, California
Santa Rosa ( Spanish for " Saint Rose") is a city and the county seat of Sonoma County, in the North Bay region of the Bay Area in California. Its estimated 2019 population was 178,127. It is the largest city in California's Wine Country and Redwood Coast. It is the fifth most populous city in the Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 25th most populous city in California. History Early history Before the arrival of Europeans, what became known as the Santa Rosa Plain was occupied by a strong and populous tribe of Pomo natives known as the Bitakomtara. The Bitakomtara controlled the area closely, barring passage to others until permission was arranged. Those who entered without permission were subject to harsh penalties. The tribe gathered at ceremonial times on Santa Rosa Creek near present-day Spring Lake Regional Park. Following the arrival of Europeans, initially Spanish explorers and colonists, the Pomos were decimated by smallpox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Francisco Bay
San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water from approximately 40 percent of California. Water from the Sacramento and San Joaquin rivers, and from the Sierra Nevada mountains, flow into Suisun Bay, which then travels through the Carquinez Strait to meet with the Napa River at the entrance to San Pablo Bay, which connects at its south end to San Francisco Bay. It then connects to the Pacific Ocean via the Golden Gate strait. However, this entire group of interconnected bays is often called the ''San Francisco Bay''. The bay was designated a Ramsar Wetland of International Importance on February 2, 2017. Size The bay covers somewhere between , depending on which sub-bays (such as San Pablo Bay), estuaries, wetlands, and so on are included in the measurement. The main part of the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Santa Rosa, California
Santa Rosa (Spanish for " Saint Rose") is a city and the county seat of Sonoma County, in the North Bay region of the Bay Area in California. Its estimated 2019 population was 178,127. It is the largest city in California's Wine Country and Redwood Coast. It is the fifth most populous city in the Bay Area after San Jose, San Francisco, Oakland, and Fremont; and the 25th most populous city in California. History Early history Before the arrival of Europeans, what became known as the Santa Rosa Plain was occupied by a strong and populous tribe of Pomo natives known as the Bitakomtara. The Bitakomtara controlled the area closely, barring passage to others until permission was arranged. Those who entered without permission were subject to harsh penalties. The tribe gathered at ceremonial times on Santa Rosa Creek near present-day Spring Lake Regional Park. Following the arrival of Europeans, initially Spanish explorers and colonists, the Pomos were decimated by smallpox bro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Sonoma County, California
Sonoma County () is a county located in the U.S. state of California. As of the 2020 United States Census, its population was 488,863. Its county seat and largest city is Santa Rosa. It is to the north of Marin County and the south of Mendocino County. It is west of Napa County and Lake County. Sonoma County comprises the Santa Rosa-Petaluma Metropolitan Statistical Area, which is part of the San Jose-San Francisco- Oakland, CA Combined Statistical Area. It is the northernmost county in the nine-county San Francisco Bay Area region. In California's Wine Country region, which also includes Napa, Mendocino, and Lake counties, Sonoma County is the largest producer. It has thirteen approved American Viticultural Areas and more than 350 wineries. The voters have twice approved open space initiatives that have provided funding for public acquisition of natural areas, preserving forested areas, coastal habitat, and other open space. More than 8.4 million tourists visit each year, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earthquakes In California
The earliest known California earthquake was documented in 1769 by the Spanish explorers and Catholic missionaries of the Portolá expedition as they traveled northward from San Diego along the Santa Ana River near the present site of Los Angeles. Ship captains and other explorers also documented earthquakes. As Spanish missions were constructed beginning in the late 18th century, earthquakes records were kept. After the missions were secularized in 1834, records were sparse until the California Gold Rush in the 1840s. From 1850–2004, there was about one potentially damaging event per year on average, though many of these did not cause serious consequences or loss of life. Since the three damaging earthquakes that occurred in the American Midwest and the East Coast ( 1755 Cape Ann, 1811–12 New Madrid, 1886 Charleston) were well known, it became apparent to settlers that the earthquake hazard was different in California. While the 1812 San Juan Capistrano, 1857 Fort Tejo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1969 Earthquakes
This year is notable for Apollo 11's first landing on the moon. Events January * January 4 – The Government of Spain hands over Ifni to Morocco. * January 5 **Ariana Afghan Airlines Flight 701 crashes into a house on its approach to London's Gatwick Airport, killing 50 of the 62 people on board and two of the home's occupants. * January 14 – An explosion aboard the aircraft carrier USS ''Enterprise'' near Hawaii kills 27 and injures 314. * January 19 – End of the siege of the University of Tokyo, marking the beginning of the end for the 1968–69 Japanese university protests. * January 20 – Richard Nixon is sworn in as the 37th President of the United States. * January 22 – An assassination attempt is carried out on Soviet leader Leonid Brezhnev by deserter Viktor Ilyin. One person is killed, several are injured. Brezhnev escaped unharmed. * January 27 ** Fourteen men, 9 of them Jews, are executed in Baghdad for spying for Israel. ** Reveren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Earthquakes In The United States
The following is a list of notable earthquakes and tsunamis which had their epicenter in areas that are now part of the United States with the latter affecting areas of the United States. Those in ''italics'' were not part of the United States when the event occurred. List of earthquakes Earthquake swarms which affected the United States: * 1962–71 Denver earthquake swarm * Enola earthquake swarm * 2008 Reno earthquakes * Guy-Greenbrier earthquake swarm * Oklahoma earthquake swarms (2009–present) Earthquakes which affected the United States but whose epicenters were outside the United States borders: * 1925 Charlevoix–Kamouraska earthquake – magnitude 6.2 earthquake, no injuries or fatalities anywhere * 1979 Imperial Valley earthquake – magnitude 6.4 earthquake with an epicenter less than 1 km inside Mexico – significant damage and injuries on both sides of the border (60 in the US) * 2010 Baja California earthquake (Mexico near S California) – magnitude ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Earthquakes In California
The earliest known California earthquake was documented in 1769 by the Spanish explorers and Catholic missionaries of the Portolá expedition as they traveled northward from San Diego along the Santa Ana River near the present site of Los Angeles. Ship captains and other explorers also documented earthquakes. As Spanish missions were constructed beginning in the late 18th century, earthquakes records were kept. After the missions were secularized in 1834, records were sparse until the California Gold Rush in the 1840s. From 1850–2004, there was about one potentially damaging event per year on average, though many of these did not cause serious consequences or loss of life. Since the three damaging earthquakes that occurred in the American Midwest and the East Coast ( 1755 Cape Ann, 1811–12 New Madrid, 1886 Charleston) were well known, it became apparent to settlers that the earthquake hazard was different in California. While the 1812 San Juan Capistrano, 1857 Fort Te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Earthquakes In 1969
This is a list of earthquakes in 1969. Only magnitude 6.0 or greater earthquakes appear on the list. Lower magnitude events are included if they have caused death, injury or damage. Events which occurred in remote areas will be excluded from the list as they wouldn't have generated significant media interest. All dates are listed according to UTC time. Maximum intensities are indicated on the Mercalli intensity scale and are sourced from United States Geological Survey (USGS) ShakeMap data. Activity generally was slightly below average with 14 events reaching magnitude 7 or greater. In August, the largest event of the year struck the Kuril Islands, Russia measuring 8.2. Other large events struck offshore Portugal and Indonesia. The Americas had no events above magnitude 7 which is an uncommon occurrence. Of the 4,000 deaths from earthquakes two events dominated. Southeastern China had an earthquake of magnitude 5.7 in July which contributed 4,024 of the total. Indonesia had th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Society Of America
The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchcock, John R. Procter and Edward Orton and has been headquartered at 3300 Penrose Place, Boulder, Colorado, US, since 1967. GSA began with 100 members under its first president, James Hall. In 1889 Mary Emilie Holmes became its first female member. It grew slowly but steadily to 600 members until 1931, when a nearly $4 million endowment from 1930 president R. A. F. Penrose Jr. jumpstarted GSA's growth. As of December 2017, GSA had more than 25,000 members in over 100 countries. The society has six regional sections in North America, three interdisciplinary interest groups, and eighteen specialty divisions. Activities The stated mission of GSA is "to advance geoscience research and discovery, service to society, stewardship of Earth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Motion
Ground motion is the movement of the earth's surface from earthquakes or explosions. Ground motion is produced by seismic waves that are generated by sudden slip on a fault or sudden pressure at the explosive source and travel through the earth and along its surface. This can be due to natural events, such as earthquakes and volcanic eruptions, or human activities, such as the detonation of nuclear weapons. There are two main types of seismic waves: body waves and surface waves. Body waves travel through the interior of the earth, while surface waves travel along the earth's surface. Ground motion is typically caused by surface waves, which are the most destructive type of seismic waves. Ground motion is measured using a seismometer A seismometer is an instrument that responds to ground noises and shaking such as caused by earthquakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The outpu . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If the angle of the fault plane is lower (often less than 15 degrees from the horizontal) and the displacement of the overlying block is large (often in the kilometer range) the fault is called an ''overthrust'' or ''overthrust fault''. Erosion can remove part of the overlying block, creating a ''fenster'' (or ''window'') – when the underlying block is exposed only in a relatively small area. When erosion removes most of the overlying block, leaving island-like remnants resting on the lower block, the remnants are called ''klippen'' (singular ''klippe''). Blind thrust faults If the fault plane terminates before it reaches the Earth's surface, it is referred to as a ''blind thrust'' fault. Because of the lack of surface evidence, blind thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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