Northern ETS Patterns

*The terms slow-slip events (SSE), episodic tremor & slip (ETS), and tremors are often used interchangeably.*

This page consists of screen snips of specific timeframes from the Pacific Northwest Seismic Network’s (PNSN) Tremor Map.

The tremor activity below is displayed in the PNSN’s “Color by Time (Jet)” option, where red is the most recent activity and blue is the oldest. This option helps illustrate how the tremor moved (migrated) from start to finish (sometimes reversing course and backtracking midway).

Note: A “geographic filter” was also used when compiling these images so that only the slow-slip (ETS) activity is shown on each image. This was done to (hopefully) make the slip area easier to compare from event to event.

Image Credit: Berkeley University

Below are screen snips of the PNSN tremor graphs showing daily “epicenter count” activity. The dates selected below coincide with the slow-slips from the slideshow above. The dates listed in the captions are hyperlinks and will take you to the PNSN’s Tremor Map with the parameters already populated for that event. This is done to help ensure the data is easily reproducible/verifiable for anyone interested in playing with the maps. Northern ETS activity for 2007 – 2009 Can be found on the PNSN’s Tremor Locations by Week & Tremor Density by ETS pages.

2010