Jim and I, and the LLO SEI crew, have been trying to figure out the best way for the seismic system to handle earthquakes and the changing environmental conditions. These two intertwine a bit and will take some more work, effort, and time to get a solution to encompass both. For now, we are going to turn on ONLY the earthquake response.
We've been running the ENV_STAT node in the background for a few months and it suggests a transition to earthquake mode in a consistent and reliable manner. Alog53985 from back in December has a few sample plots for what this response looks like. Today, we've changed the name of the node from ENV_STAT to SEI_ENV, which will now manage SEI_CONF. The conditions for when SEI_ENV will transition are currently as follows:
- SEISMON produces an alert that falls into our earthquake area on the SEIPlot. We are then transitioned to the state PREP_FOR_EARTHQUAKE. When SEI_ENV begins to see the Z peakmon channel (H1:ISI-GND_STS_CS_Z_EQ_PEAK_OUTMON) get above 400 that it will request for SEI_CONF to transition to Earthquake.
- Or if there is no SEISMON alert, but the peakmon signal gets above 1000, then it will immediately request SEI_CONF to go to the Earthquake.
Once in earthquake, it will stay here until the peakmon signal stays below a slightly higher threshold for 10 minutes. It will then transition SEI_CONF back to its nominal state.
There is more work to be done here to handle the more extreme environment cases, but this will be a good start.