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| | Broadband Seismic Data Collection Center, IGPP, UCSD | Frequently Asked Questions | The Shadow Zone (Site not responding. Last check: 2007-10-24) |
 | | This section of the earth of poor seismic information, or 'shadow zone', is defined as the area of the earth from angular distances of 104° to 140° to the epicenter that, for a given earthquake, does not experience seismic waves. |
 | | The shadow zone results from S waves being unable to transmit through the liquid core and P waves being bent (refracted) by the liquid outer core. |
 | | No, although earthquakes often occur around the world in locations that position the Anza broadband array in the epicenter's shadow zone, earthquakes are measured by multiple broadband arrays across the globe. |
| eqinfo.ucsd.edu /faq/shadow_zone.html (425 words) |
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