CTC Results Pre-2012

CTC ShakeAlert and ShakeCast Testing

As of September 2011, CISN Testing Center (CTC) processing now evaluates performance of the prototype CISN ShakeAlert EEW system. CTC evaluations are now based on earthquake parameter forecasts as logged by the CISN ShakeAlert system at U.C. Berkeley.

This testing include inputs from three algorithms (UCB Elarms, ETH Virtual Seismologist, and Caltech Onsite) as well as processing outputs from the ShakeAlert Decision Module.

The CTC automated testing center uses the following processing steps in its evaluation:

1. Evaluations are run once per day.
2. In order to let evaluation EEW alerts against "final" "stable" earthquake parameters, evaluations are delay for two days. That is on Tuesday, evaluations are done for the previous Sunday.
3. Evaluation processing retrieves observed earthquake information from the ANSS catalog.
4. ANSS catalog entries are filtered and earthquake below Mag 2.5 or outside the state of California are discarded.
5. Evaluation processing retrieves ShakeAlert log files from operational server at UCB.
6. For each ANSS earthquake, we look for one or more ShakeAlert triggers with origin time within 45 seconds of the observed earthquake.
7. Plots are produced showing final (observed, ANSS) magnitude as compared to algorithm alerts from VS, OnSite, and ElarmS and Decision Module alerts (as sent to users).

The automated nightly evaluation results are posted at the following location.

• CTC Automated Daily ShakeAlert Testing Results
• CTC Automated Daily ShakeCast Testing Results