The Pacific Northwest Seismic Network, or PNSN, collects and studies ground motions from about 400

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 ...

s in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...

s of

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

and

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

. PNSN monitors

volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

and

tectonic Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...

activity, gives advice and information to the public and policy makers, and works to mitigate

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

hazard.

Motivation

Damaging earthquakes are well known in the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

, including several larger than magnitude 7, most notably the M9

1700 Cascadia earthquake 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 P ...

and the M7.0–7.3 earthquake in about 900AD on the

Seattle Fault The Seattle Fault is a zone of multiple shallow east–west thrust faults that cross the Puget Sound Lowland and through Seattle (in the U.S. state of Washington) in the vicinity of Interstate Highway 90. The Seattle Fault was first recognized as ...

. The M6.5

1965 Puget Sound earthquake The 1965 Puget Sound earthquake occurred at 08:28 AM PDT (15:28 UTC) on April 29 within the Puget Sound region of Washington state. It had a magnitude of 6.7 on the moment magnitude scale and a maximum perceived intensity of VIII (''Severe'') ...

shook the

Seattle, Washington Seattle ( ) is a port, seaport city on the West Coast of the United States. It is the county seat, seat of King County, Washington, King County, Washington (state), Washington. With a 2020 population of 737,015, it is the largest city in bo ...

area, causing substantial damage and seven deaths. This event spurred the installation of the Pacific Northwest Seismic Network in 1969 to monitor regional earthquake activity. Early in 1980 PNSN scientists detected unrest under Mt. St. Helens and by March 1980 predicted an eruption was likely to occur "soon". On March 27th the first steam and ash explosion occurred. The PNSN expanded to better monitor Mt. St. Helens and other Cascade Volcanos leading up to the deadly May 18 eruption and in the years following.

Observations and efficacy

Earthquakes are recorded frequently beneath

Mount St. Helens Mount St. Helens (known as Lawetlat'la to the indigenous Cowlitz people, and Loowit or Louwala-Clough to the Klickitat) is an active stratovolcano located in Skamania County, Washington, in the Pacific Northwest region of the United St ...

Mount Rainier Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a s ...

, and

Mount Hood Mount Hood is a potentially active stratovolcano in the Cascade Volcanic Arc. It was formed by a subduction zone on the Pacific coast and rests in the Pacific Northwest region of the United States. It is located about east-southeast of Portlan ...

. After successfully using seismic activity to predict the 1980 Mt. St. Helens eruption, monitoring was expanded to other

Cascade Mountains The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

volcanoes. The PNSN, in conjunction with the

Cascades Volcano Observatory The David A. Johnston Cascades Volcano Observatory (CVO) is a volcano observatory in the US that monitors volcanoes in the northern Cascade Range. It was established in the summer of 1980, after the eruption of Mount St. Helens.USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

, now monitors seismicity at all the Cascade volcanoes in Washington and Oregon. The network was significantly expanded after the damaging

2001 Nisqually earthquake The 2001 Nisqually earthquake occurred at on February 28, 2001 and lasted nearly a minute. The intraslab earthquake had a moment magnitude of 6.8 and a maximum Mercalli intensity of VIII (''Severe''). The epicenter was in the southern Puget So ...

. After an earthquake on January 30, 2009 the network's emergency notification system failed. A magnitude 4.3 earthquake in February 2015 showed that the present architecture of the network results in a significant delay in the early warning notification program, depending upon the location of the quake, leading to proposals to again expand the network. The early warning notification program was implemented with its reliability contingent upon unknown future funding, but with the election of

Donald Trump Donald John Trump (born June 14, 1946) is an American politician, media personality, and businessman who served as the 45th president of the United States from 2017 to 2021. Trump graduated from the Wharton School of the University of Pe ...

"future funding is uncertain" according to Washington Congressman

Derek Kilmer Derek Christian Kilmer (born January 1, 1974) is an American politician who has been the U.S. representative for Washington's 6th congressional district since 2013. A member of the Democratic Party, he served as a member of the Washington House ...

. The president's budget for the fiscal year commencing October 1, 2018 calls for reductions in funding and staff for the early warning notification program.

Operations and data archiving

The network operates from the Earth and Space Sciences Department at the

University of Washington The University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seattle a ...

in Seattle, and its data archiving is at the Data Management Center of the

IRIS Consortium IRIS (Incorporated Research Institutions for Seismology) is a university research consortium dedicated to exploring the Earth's interior through the collection and distribution of seismographic data. IRIS programs contribute to scholarly research, ...

in Seattle. The network is also affiliated with the

University of Oregon The University of Oregon (UO, U of O or Oregon) is a public research university in Eugene, Oregon. Founded in 1876, the institution is well known for its strong ties to the sports apparel and marketing firm Nike, Inc, and its co-founder, billion ...

Department of Geology. It is the second largest of the regional seismic networks in the ANSS (

Advanced National Seismic System 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 (generally within 10 ...

) and has produced more data than the networks in the states of

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

and the New Madrid, Missouri-Tennessee-Kentucky-Arkansas area. The network is funded primarily by the

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

, which stations its own staff on the campus, and the network is managed by UW staff. Additional funding is provided by the

Department of Energy A Ministry of Energy or Department of Energy is a government department in some countries that typically oversees the production of fuel and electricity; in the United States, however, it manages nuclear weapons development and conducts energy-rel ...

, the

State of Washington Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...

, and the

State of Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

References

{{Reflist

External links

Pacific Northwest Seismic Network
(official website)

–

ShakeAlert Implementation Plan
–

Seismological observatories, organisations and projects Seismic networks University of Oregon Earthquake engineering Geology of Washington (state) Geology of Oregon University of Washington projects