Презентация на тему Utilization of seismic and infrasound signals forcharacterizing mining explosions

Box - (JB): A NEMA-4 enclosure that houses essential acquisition

and communications equipment including the Paladin® digital seismic recorder which serves as the backbone of ESG’s microseismic data acquisition system.
Ethernet communication: Fiber (underground) or radio (surface) for reliable, full waveform data transfer.
Acquisition PC: Acquisition Server, watchdog, optional large external storage drive and uninterruptable power supply (UPS).
Processing PC: Fast multi-core Processor and powerful dedicated video card.

element 03 of PDAR (360 km range) from contained

singlefired explosions, delay-fired cast blasts and delay-fired coal shots

at EYMN (Ely, Minnesota) from taconite fragmentation explosions approximately 110

km to the southwest of the station.

Morenci are compared to total amount of explosives used

in copper fragmentation blasts (left). Peak Pg, Lg and Rg amplitudes observed at the regional station TUC plotted against total amount of explosives used in the Morenci copper fragmentation explosions (right).

mining explosion source model are represented pictorially. They consist of

(a) the directly coupled energy from the contained explosion modeled as a Mueller-Murphy source function, (b) vertical spall due to the tensile failure of near-surface materials and (c) horizontal spall accompanying cast blasting when overburden is cast horizontally into a pit.

taconite hard rock explosions (open diamonds) and a single

coal cast blast (star) was estimated from blasting logs. These empirical estimates from mining explosions are compared to the Viecelli and Sobel spall mass scaling relations developed for underground nuclear explosions.

used to produce synthetics for a distance and crustal

velocity model appropriate for EYMN. Synthetics were produced for a number of mining explosions of different average charge weight per borehole. Peak amplitudes of the synthetics are compared to the observations from the same explosions.

also used to compute synthetics for the large-scale cast

blasts. The focus in this modeling exercise is on the long period surface waves.

copper mines in southeastern Arizona generate infrasound signals as

exemplified by the records from DLIAR in Los Alamos (left). Ground truth for this event was provided by close-in seismic and acoustic records of the blast (left, inset). Frequency wave number estimates were used to make the back azimuth estimate shown to the right.

data (channel 4) from a seismo-acoustic station installed outside El

Paso, Texas (Ft. Hancock). Each horizontal section represents 10 minutes of data. This seismo-acoustic signal that extends for over 30 minutes represents the explosion and burning of a natural gas line in New Mexico

1-3) and seismic (channel 4) signals from the gas explosion

are shown to the left. These signals are compared to close-in seismic signals of the blast shown to the right (courtesy of T. Wallace). Both the close-in seismic and the infrasound signals suggest a complex source function for the initial explosion. The seismo-acoustic station at Ft. Hancock has porous and slow velocity alluvium at the surface that may be responsible for the strong coupling between the infrasound and seismic channels.