ShakeAlert Performance Testing System Overview

1. ShakeAlert Performance Testing System Overview CISN Testing Center (top right) retrieves a daily earthquake catalog from ANSS Data Center (bottom right) and ShakeAlert performance logs from U.C. Berkeley (left). It then matches new ANSS events to Algorithm Alerts and Decision Module Alerts and plots (1) Event Performance summaries, and (2) Cumulative Performance Summaries

2. Types of ShakeAlert Performance Summaries Currently Available Summaries posted online at: http://scec.usc.edu/scecpedia/CTC_Results

3. Useful Information to Help Interpretation of CTC Performance Summary Results • CTC performance summaries are focused on ShakeAlert speed of operation and earthquake event parameter forecasts. No site specific ground motion performance summaries have been developed. • CTC ShakeAlert performance summaries compare ANSS event parameters to ShakeAlert alert event parameter forecasts. No searching for “false alerts” is currently done. • Because ANSS Catalog is considered the correct observation, the CTC waits 48 hours after events to let the ANSS catalog settle down before generating CTC performance summaries. • Cumulative summaries depend on the catalog filter criteria (date range, magnitude, and region) used to select ANSS catalog events. Currently, ANSS events are selected for Mag >= 3.5, Network ID NC or CI. And, we currently run for two time frames Sept 2011 through present and March 3, 2012 through present (considered the Elarms2 era). • One pager event summaries are produced for new all ANSS events with Network ID NC or CI and Mag >= 3.0