417 words used in the labs.

Find a term from the labs, understand the process behind it, and see how it appears in the landscape. Each entry connects an explanation with a real observation and a model you can explore.

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Term

P-wave

Also written: Primary / compressional wave

A compressional seismic wave with particle motion parallel to its travel direction. It travels through solids and liquids and is the faster body-wave type.

What to look for

USGS seismometer installation in Puerto Rico. Wave arrival times and recorded ground motion are used to estimate an earthquake's focus, epicentre and magnitude; none of those buried locations is visible in this photograph.

Related labs

Earth’s interior →Earthquakes →

Mark understood

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Explore further with USGS water glossary · USGS volcano glossary · NPS glacial geology · NASA Earth facts. Photograph acknowledgements are collected on the Image credits page.