earth science

Pacific Northwest Seismic Network

Pacific Northwest Seismic Network is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Pacific Northwest Seismic Network rather than just read about it. In short: The Pacific Northwest Seismic Network, or PNSN, collects and studies ground motions from about 400 seismometers in the U.S. states of Oregon and Washington. PNSN monitors volcanic and tectonic activity, gives advice and information to the public and policy makers, and works to mitigate earthquake hazard.

Key takeaways

Pacific Northwest Seismic Network belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Pacific Northwest Seismic Network to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Pacific Northwest Seismic Network from memory before moving on to harder problems.

Reference excerpt

The Pacific Northwest Seismic Network, or PNSN, collects and studies ground motions from about 400 seismometers in the U.S. states of Oregon and Washington. PNSN monitors volcanic and tectonic activity, gives advice and information to the public and policy makers, and works to mitigate earthquake hazard.

Motivation Damaging earthquakes are well known in the Pacific Northwest, including several larger than magnitude 7, most notably the M9 1700 Cascadia earthquake and the M7.0–7.3 earthquake in about 900AD on the Seattle Fault. The M6.5 1965 Puget Sound earthquake shook the Seattle, Washington, 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 27 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 Rainier, and Mount Hood. After successfully using seismic activity to predict the 1980 Mt. St. Helens eruption, monitoring was expanded to other Cascade Mountains volcanoes. The PNSN, in conjunction with the Cascades Volcano Observatory of the USGS, now monitors seismicity at all the Cascade volcanoes in Washington and Oregon. The network was significantly expanded after the damaging 2001 Nisqually earthquake. 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 "future funding is uncertain" according to Washington Congressman Derek Kilmer. 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 in Seattle, and its data archiving is at the Data Management Center of the IRIS Consortium in Seattle. The network is also affiliated with the University of Oregon Department of Geology. It is the second largest of the regional seismic networks in the ANSS (Advanced National Seismic System) and has produced more data than the networks in the states of Alaska, Utah, Nevada, Hawaii and the New Madrid, Missouri-Tennessee-Kentucky-Arkansas area. The network is funded primarily by the United States Geological Survey, 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, the State of Washington, and the State of Oregon.

References

External links Pacific Northwest Seismic Network (official website) PNSN—Pacific Northwest Seismograph Network – United States Geological Survey ShakeAlert Implementation Plan – United States Geological Survey

Worked examples

Example 1 — a first encounter with Pacific Northwest Seismic Network

Start with the simplest possible case. Write down what Pacific Northwest Seismic Network claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Pacific Northwest Seismic Network before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Pacific Northwest Seismic Network ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Pacific Northwest Seismic Network

In research: Pacific Northwest Seismic Network appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Pacific Northwest Seismic Network in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Pacific Northwest Seismic Network is common in secondary-school and first-year university syllabi. It links to neighbouring topics Earthquake engineering, Geology of Oregon, Geology of Washington (state), so understanding it makes those chapters shorter.
In everyday life: Look for Pacific Northwest Seismic Network outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Pacific Northwest Seismic Network in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pacific Northwest Seismic Network means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Pacific Northwest Seismic Network out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pacific Northwest Seismic Network in simple terms?

Why does Pacific Northwest Seismic Network matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Pacific Northwest Seismic Network?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Pacific Northwest Seismic Network.