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The following figures show two modeled measures of network capability

Global Network Capability. The following figures show two modeled measures of network capability Minimum magnitude detection threshold Network detection time For four network configurations: 1. GSN, ANSS (IU, II, US) 2. IMS (IM) + GSN, ANSS (IU, II, US)

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The following figures show two modeled measures of network capability

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  1. Global Network Capability The following figures show two modeled measures of network capability Minimum magnitude detection threshold Network detection time For four network configurations: 1. GSN, ANSS (IU, II, US) 2. IMS (IM) + GSN, ANSS (IU, II, US) 3. GEOFON (GE) + IMS (IM) + GSN, ANSS (IU, II, US) 4. All NEIC Real-Time: Others (G, AK…) + GEOFON (GE) + IMS (IM) + GSN, ANSS (IU, II, US)

  2. Detection Threshold Method The minimum Mw level for each grid cell is modeled by computing the minimum Brune earthquake amplitude that exceeds ambient noise levels at 9 stations. Mo = 2.29r3 dyne-cm (Brune 1970, 1971) Mw = 0.667 log(Mo) – 10.7 (Kanimori, 1977). (Brune 1970, 1971) Fc=0.25s, Mw=4.0 fc=1Hz (1s), Mw=5.1 dB = 10log(As2) PDF Median For each path determine min Mw exceeding station PDF mode. References: McNamara, D.E., and R. Buland, ANSS Detection threshold, 15th Annual IRIS Workshop, 19-21 June, Yosemite, CA, 2003. McNamara, D. E. and R.P. Buland, Ambient noise levels in the continental US, Bull. Seism. Soc. Am., 94, 4, 1517-1527, 2004.

  3. Network Detection Threshold: GSN, ANSS The map to the left shows the minimum moment magnitude (Mw) detectable in each 1 degree grid cell by the first 9 stations in the GSN (II, IU) and ANSS (US) networks. Ambient noise levels are taken from the median of the PDF distribution for several years of BHZ noise observations.

  4. Network Detection Threshold: GSN, ANSS, IMS The map to the left shows the minimum moment magnitude (Mw) detectable in each 1 degree grid cell by the first 9 stations in the GSN (II, IU), ANSS (US) and IMS (IM) networks.. Ambient noise levels are taken from the median of the PDF distribution for several years of BHZ noise observations. Improvements are notable in Asia, Australia and less so in South America and Africa.

  5. Network Detection Threshold: GSN, ANSS, IMS, GEOFON The map to the left shows the minimum moment magnitude (Mw) detectable in each 1 degree grid cell by the first 9 stations in the GSN (II, IU), ANSS (US), IMS (IM) and GEOFON (GE) networks.. Ambient noise levels are taken from the median of the PDF distribution for several years of BHZ noise observations. Improvements are notable in Europe, Indonesia and Australia.

  6. Network Detection Time: NEIC Real-Time This model includes all 495 real-time stations received by the NEIC with accurate instrument response meta-data. This includes global (G), national (CN, AU) and regional (AK, CI, CU, PR) networks. Improvements are notable in the Caribbean, N. Africa, Europe, Indonesia and Australia.

  7. Network Detection Time: GSN, ANSS The map to the left shows the time in minutes for a P-wave from the smallest earthquake in each 1 degree grid cell to be detected by the first 9 stations with the GSN (II, IU) and ANSS (US) networks. The P-wave travel time for an earthquake in each grid cell is modeled with the Tau-P method using the IASPEI91 Earth model. Detecting station distribution is determined from the minimum Mw detection results from the previous slides.

  8. Network Detection Time: GSN, ANSS, IMS The map to the left shows the time in minutes for the initial P-wave from an earthquake in each cell to be detected by the first 9 stations in the GSN (II, IU), ANSS (US) and IMS (IM) networks . Improvements are notable in Asia, Australia and less so in South America and Africa.

  9. Network Detection Time:GSN, ANSS, IMS, GEOFON The map to the left shows the time in minutes for the initial P-wave from an earthquake in each cell to be detected by the first 9 stations in the GSN (II, IU), ANSS (US), IMS (IM) and GEOFON (GE) networks . Improvements are notable in Europe, Indonesia and Australia.

  10. Network Detection Time: NEIC Real-Time This model includes all 495 real-time stations received by the NEIC with accurate instrument response meta-data. This includes global (G), national (CN, AU) and regional (AK, CI, CU, PR) networks. Improvements are notable in the Caribbean, N. Africa, Europe, Indonesia and Australia.

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