The Pacific Northwest Seismic Network (PNSN) has installed a seismic monitoring station at the Lake Cavanaugh Community Center! The station is named LKCAV.
The purpose of LKCAV is to monitor and record local earthquake activity. The type of sensor installed at Lake Cavanaugh does this by measuring very small changes in the velocity (acceleration) of the ground beneath the sensor. It measures these velocities in 3 different directions. Along the N-S axis, the E-W axis and the vertical axis, giving scientists a 3-D perspective of ground motion. The seismic data from the sensor at Lake Cavanaugh are sent via internet to the PNSN at the University of Washington for rapid analysis.
In addition to monitoring earthquake activity, LKCAV supports the ShakeAlert Earthquake Early Warning Project operated in partnership with the United States Geological Survey-which provides warnings to the citizens of Washington, Oregon and California. ShakeAlert uses the rapid detection of seismic waves to deliver alerts before the shaking reaches people, providing citizens with valuable seconds, or even minutes, to prepare. Using data from the nearly 700 seismic stations operated by the PNSN, including LKCAV, ShakeAlert can detect an earthquake just 3-5 seconds after it begins.
Ground motion data collected by LKCAV is available to the public via the PNSN’s website
The PNSN is the federally recognized authority on earthquake activity in the Pacific Northwest, tasked with maintaining a network of over 650 seismic stations across Washington and Oregon. The PNSN is comprised of a team of scientists, engineers, and IT specialists from the University of Washington, University of Oregon, and the United States Geological Survey, with headquarters on the University of Washington Campus.
Above is a seismogram depicting the acceleration measured at the station from April 22, 2025. Here are some tips for making sense of the data!
- Our sensors measure acceleration in an east-west plane, north-south plane, and the vertical plane. This seismogram is focused on acceleration in the vertical plane…places where the squiggly lines get bigger indicate times where acceleration of the ground in the vertical plane has increased.
- The times in Pacific Standard are on the left axis, the times in UTC are on the right axis.
- Each line represents a 15-minute increment. The lines have different colors simply to make the chart more readable.
- Earthquakes are not the only thing that can cause the squiggles. These are very sensitive instruments. Activities like walking around the sensor, driving on nearby roads, or HVAC systems all cause ground motion. Taking this into account when looking at the seismogram, it looks like there is some sort of ventilation system, or HVAC system that kicks on for a few minutes every 15-20 minutes. It also looks like someone may have been onsite around 7pm last night, and then again today at 1pm.
- There is no set scale for these seismograms, it adjusts based on the amount of ground motion at a site. For example, if an earthquake was recorded by LKCAV, the amount of acceleration associated would be significantly more than the acceleration caused by someone walking around the building. To reflect the earthquake the scale of the seismogram would be increased, essentially smoothing out all of the smaller non-seismic ground motion.