Pawnee County is a county located in the U.S. state of Oklahoma. As of the 2010 census, the population was 16,577. Its county seat is Pawnee. The county is named after the Pawnee Nation, whose reservation used to encompass the county prior to allotment in 1893.
Inola is a town in Rogers County, Oklahoma, United States. It is included in the Tulsa Metropolitan Statistical Area (TMSA). The population was 1,788 at the 2010 census, a 12.5 percent increase from 1,589 at the 2000 census. Inola is a Cherokee word meaning "Black Fox." The town styles itself as "The Hay Capital of the World."
Amchitka is a volcanic, tectonically unstable and uninhabited island in the Rat Islands group of the Aleutian Islands in southwest Alaska. It is part of the Alaska Maritime National Wildlife Refuge. The island, with a land area of roughly 116 square miles (300 km2), is about 42 miles (68 km) long and 1 to 4 miles wide. The area has a maritime climate, with many storms, and mostly overcast skies.
Induced seismicity refers to typically minor earthquakes and tremors that are caused by human activity that alters the stresses and strains on Earth's crust. Most induced seismicity is of a low magnitude. A few sites regularly have larger quakes, such as The Geysers geothermal plant in California which averaged two M4 events and 15 M3 events every year from 2004 to 2009. The Human-Induced Earthquake Database (HiQuake) documents all reported cases of induced seismicity proposed on scientific grounds and is the most complete compilation of its kind.
The Lamont–Doherty Earth Observatory (LDEO) is the scientific research center of the Columbia Climate School, and a unit of The Earth Institute at Columbia University. It focuses on climate and earth sciences and is located on a 189-acre campus in Palisades, New York, 18 miles (29 km) north of Manhattan on the Hudson River.
POLARIS (PUPS) was an underground experiment to observe seismic signals at depth in very hard rock. It was carried out at SNOLAB, and underground physics laboratory, in Sudbury, Ontario. In addition to academic research, the observational data collected by the POLARIS system was used by the Canadian National Data Centre (CNDC) for earthquake, and nuclear explosion monitoring. The name POLARIS is an acronym for Portable Observatories for Lithospheric Analysis and Research Investigating Seismicity.
The focal mechanism of an earthquake describes the deformation in the source region that generates the seismic waves. In the case of a fault-related event it refers to the orientation of the fault plane that slipped and the slip vector and is also known as a fault-plane solution. Focal mechanisms are derived from a solution of the moment tensor for the earthquake, which itself is estimated by an analysis of observed seismic waveforms. The focal mechanism can be derived from observing the pattern of "first motions", that is, whether the first arriving P waves break up or down. This method was used before waveforms were recorded and analysed digitally and this method is still used for earthquakes too small for easy moment tensor solution. Focal mechanisms are now mainly derived using semi-automatic analysis of the recorded waveforms.
Body-waves consist of P-waves that are the first to arrive, or S-waves, or reflections of either. Body-waves travel through rock directly.
The South West Seismic Zone is a major intraplate earthquake province located in the south west of Western Australia. It was known earlier as the Yandanooka – Cape Riche Lineament, corresponds to the physiographic boundary known as the Meckering Line, and also the junction between Swanland and Salinaland.
The zone exists within an Archaean Shield structure called the Yilgarn Block. The identified geological subdivisions within this Precambrian structure do not show an obvious relation to the seismicity.
The 2011 Oklahoma earthquake was a 5.7 magnitude intraplate earthquake which occurred near Prague, Oklahoma on November 5 at 10:53 p.m. CDT in the U.S. state of Oklahoma. The epicenter of the earthquake was in the vicinity of several active wastewater injection wells. According to the United States Geological Survey (USGS), it was the most powerful earthquake ever recorded in Oklahoma; this record was surpassed by the 2016 Oklahoma earthquake. The previous record was a 5.5 magnitude earthquake that struck near the town of El Reno in 1952. The quake's epicenter was approximately 44 miles (71 km) east-northeast of Oklahoma City, near the town of Sparks and was felt in the neighboring states of Texas, Arkansas, Kansas and Missouri and even as far away as Tennessee and Wisconsin. The quake followed several minor quakes earlier in the day, including a 4.7 magnitude foreshock. The quake had a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale in the area closest to the epicenter. Numerous aftershocks were detected after the main quake, with a few registering at 4.0 magnitude.
The Conrad Observatory is an underground geophysical research facility of the Central Institution for Meteorology and Geodynamics (ZAMG) in Austria. The basic task of the observatory is monitoring relevant physical parameters that are of decisive importance for our understanding of processes on and below earth. At the Conrad Observatory, seismic activities (seismology), variations in gravitational acceleration and mass changes (gravimetry), magnetic field variations, geodetic parameters, atmospheric waves, as well as meteorological data are continuously monitored.
On 12 February 2013, North Korean state media announced it had conducted an underground nuclear test, its third in seven years. A tremor that exhibited a nuclear bomb signature with an initial magnitude 4.9 was detected by the China Earthquake Networks Center, Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization and the United States Geological Survey. In response, Japan summoned an emergency United Nations meeting for 12 February and South Korea raised its military alert status. It is not known whether the explosion was nuclear or a conventional explosion designed to mimic a nuclear blast; as of two days after the blast, Chinese, Japanese, and South Korean investigators had failed to detect any radiation.
Harry Oscar Wood (1879–1958) was an American seismologist who made several significant contributions in the field of seismology in the early twentieth-century. Following the 1906 earthquake in San Francisco, California, Wood expanded his background of geology and mineralogy and his career took a change of direction into the field of seismology. In the 1920s he co-developed the torsion seismometer, a device tuned to detect short-period seismic waves that are associated with local earthquakes. In 1931 Wood, along with another seismologist, redeveloped and updated the Mercalli intensity scale, a seismic intensity scale that is still in use as a primary means of rating an earthquake's effects.
Geophysical Service of the Russian Academy of Sciences is a research body responsible for geological research.
The Oklahoma earthquake swarms are an ongoing series of human activity-induced earthquakes affecting central Oklahoma, southern Kansas, northern Texas since 2009. Beginning in 2009, the frequency of earthquakes in the U.S. state of Oklahoma rapidly increased from an average of fewer than two 3.0+ magnitude earthquakes per year since 1978 to hundreds each year in the 2014–17 period. Thousands of earthquakes have occurred in Oklahoma and surrounding areas in southern Kansas and North Texas since 2009. Scientific studies attribute the rise in earthquakes to the disposal of wastewater produced during oil extraction that has been injected more deeply into the ground.
The 1980 Eureka earthquake occurred on November 8 at along the northern coastal area of California in the United States. With a moment magnitude of 7.3 and a maximum Mercalli intensity of VII, this strike-slip earthquake was the largest to occur in California in 28 years. Although damage was considered light, several loss estimates equaled or exceeded $2 million, and six injuries resulted when two vehicles came down with the partial collapse of a highway overpass on US 101 in Fields Landing. The north coast of California experiences frequent plate boundary earthquakes near the Mendocino Triple Junction and intraplate events also occur within the Gorda Plate.
The Oklahoma Geological Survey is a state agency chartered in the Constitution of Oklahoma responsible for collecting and disseminating information about Oklahoma's natural resources, geological formations, and earthquakes. Shortly after Oklahoma became a state, its first legislature passed an enabling act on May 29, 1908 and Governor Charles Haskell signed it into law. The OGS was an offshoot of Oklahoma Territory's Territorial Survey, which was established in 1900. OGS remains the only state geological survey that was created by a provision in the state constitution. In 1924, jurisdiction of the OGS was officially put under the Oklahoma University Board of Regents, and has not been changed since. In 2007, OGS became part of the Mewbourne College of Earth and Energy.
The 2016 Oklahoma earthquake occurred on September 3, 2016 near Pawnee, Oklahoma. Measuring 5.8 on the moment magnitude scale, it is the strongest in state history. At 5.8 magnitude, this ties it with the 2011 Virginia earthquake, which was determined after it struck to be the most powerful quake in the eastern United States in the preceding 70 years.
The Advanced National Seismic System (ANSS) is a collaboration of the U.S. Geological Survey (USGS) and regional, state, and academic partners that collects and analyzes data on significant earthquakes to provide near real-time information to emergency responders and officials, the news media, and the public. Such information is used to anticipate the likely severity and extent of damage, and to guide decisions on the responses needed.
