Part II: The new Malargüe seismic array IS@AO Workshop, Cambridge, April 19 th 2011 Elmer Ruigrok,...
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Transcript of Part II: The new Malargüe seismic array IS@AO Workshop, Cambridge, April 19 th 2011 Elmer Ruigrok,...
Part II: The new Malargüe seismic array
IS@AO Workshop, Cambridge, April 19th 2011
Elmer Ruigrok, Deyan Draganov and Kees Wapenaar
MalaRRgue
• MalaRRgue: A large seismic array in the Malargüe department
• Partial collocation with Pierre Auger Observatory• 2012: temporary array of 80 stations• >=2013: ‘permanent’ array • Monitoring and imaging the subsurface• Application of recently developed techniques• International team of geophysicists
ICES
The missing seismic array …
Swell
Local waves
Oceanic -> seismic waves Beamforming seismic waves -> sea state
Ocean waves Seismic arrays (Koper et al., 2010)
MalaRRgue, aim 1: monitoring the southern oceans
Peteroa volcano
MalaRRgue, aim 2: imaging and monitoring the Peteroa volcano
Volcano activity, September 2010
Imaging challenges still to be addressed
(Gilbert et al., 2006)
Malargüe
• Known– Moho depth
• Our imaging targets– Moho topography– Basin topography– Nazca slab depth– Magma intrusions– Major faults
MalaRRgue, aim 3: detailed imaging of the lithosphere
Example response selection
Time-window and separate pre-processing
P and reverberations
PP and reverberations
Further processing
Subsurface reflectivity image (example)
New method: seismic interferometry, output
A dense sensor network
Malargüe
T-array– 2 orthogonal linear subarrays– 3 km inline spacing– 42 stations – ‘Basin’ setting
Illumination by earthquakes and storms
I: Inline earthquakes
II: Inline oceanic storms (Landes et al., 2010)
High-resolution subsurface imaging
1. Reflection imaging instead of conversion imaging
2. Dense sensor network
3. Using not only earthquake responses, but also storm-induced waves
Summary
Large seismic array (80 stations) planned in the Malargüe department
1. Imaging subsurface
2. Monitoring the sea state in the SH
3. Monitoring volcanic activity
4. Monitoring local seismicity
PAO synergies
• Facility and expertise exchange
• Coupling atmospheric gravity waves with seismic waves?
• Coupling lightening to seismic waves?