Open AccessThree‐dimensional location and waveform analysis of microseismicity in multi‐anvil experiments
Author(s) -
De Ronde A. A.,
Dobson D. P.,
Meredith P. G.,
Boon S. A.
Publication year - 2007
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2007.03597.x
Subject(s) - geology , waveform , seismology , compression (physics) , acoustic emission , acoustics , materials science , computer science , telecommunications , physics , radar , composite material
SUMMARY We present an acoustic emission (AE) monitoring technique to study high‐pressure ( P > 1 GPa) microseismicity in multi‐anvil rock deformation experiments. The application of this technique is aimed at studying fault mechanisms of deep‐focus earthquakes that occur during subduction at depths up to 650 km. AE monitoring in multi‐anvil experiments is challenging because source locations need to be resolved to a submillimetre scale due to the small size of the experimental assembly. AEs were collected using an 8‐receiver array, located on the back truncations of the tungsten carbide anvils. Each receiver consists of a 150–1000 kHz bandwidth PZT transducer assembly. Data were recorded and processed using a high‐speed AMSY‐5 acquisition system from Vallen‐Systems, allowing waveform collection at a 10 MHz sampling rate for each event signal. 3‐D hypocentre locations in the assembly are calculated using standard seismological algorithms. The technique was used to monitor fault development in 3 mm long × 1.5 mm diameter olivine cores during axisymmetric compression and extension. The faults were generated during cold compression to ∼2 GPa confining pressure. Subsequent AEs at 2–6 GPa and 900 °C were found to locate near these pre‐existing faults and exhibit high pressure stick‐slip behaviour.