Discriminating ripple-fire explosions with high frequency (>20 Hz) data

Conference · Mon Apr 01 04:00:00 EST 1996

OSTI ID:221917

Carr, D B; Garbin, H D

With a Comprehensive Test Ban (CTB), discriminating ripple-fired explosions from mining operations becomes important. Different methods have been proposed to discriminate these explosions, most of which use the modulations seen in the spectra of ripple-fired blasts. The Deployable Seismic Verification System (DSVS) in Wyoming records data at frequencies up to 50 Hz, and provides an opportunity to determine if there are any operational benefits to discriminate ripple-fired explosions from using high frequency (> 20 Hz) data. We collected a database of 646 events consisting of 118 known earthquakes, 1 known rockburst, 176 known ripple-fired quarry blasts and 351 unknown signals. Binary spectrograms for each event were calculated using a 2.5 second window, 5/8 overlap and 10% cosine window. We used a frequency band of 0 to 50 Hz. A blind test was done to choose events that appeared to have spectral banding indicative of ripple-fire explosions. One hundred fifty one events were picked as ripple-fire explosions by both authors; 59 of these events are known quarry blasts. To remove the ambiguities introduced using human analysts, we calculated an average binary spectrum for each event following a method similar to Wuster (1993). A criterion was developed so that events with six or more peaks over 0.8 and/or nulls under 0.2 was declared a ripple-fire explosion. With this method, 251 events were chosen as ripple-fire explosions, 91 of them known quarry blasts.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 221917
• Report Number(s): SAND--96-0179C; CONF-9604115--1; ON: DE96008877
• Country of Publication: United States
• Language: English

Related Subjects

35 ARMS CONTROL
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
ARMS CONTROL
DISTANCE
EARTHQUAKES
HZ RANGE
NUCLEAR EXPLOSION DETECTION
ROCK BURSTS
SEISMIC DETECTION
UNDERGROUND EXPLOSIONS
VERIFICATION