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70 Years of Seismology at DTM
Shaun Hardy and Louis Brown Carnegie Institution for Science
Neighborhood Lecture Series April 25, 2019
DTM seismic truck with instruments for recording waves from “artificial earthquakes.” Controlled explosions were set off across the Mid-Atlantic region to probe Earth’s crust.
Hypothetical crustal structure beneath Washington DC from DTM’s earliest explosion seismology experiments.
Detonation of depth charge from a Coast Guard cutter in Puget Sound during joint DTM-GL seismic experiment.
Seismic equipment set up on a railroad flatcar during DTM’s seismic expedition to Alaska and Yukon Territory.
Truck with seismic equipment and radio receiver deployed in Peru during the Carnegie Andes Expedition.
Explosion set off in an open-pit copper mine in Peru for Carnegie’s seismological studies of the Andes
during the International Geophysical Year.
DTM cooperative seismic network for the study of local earthquakes. Nineteen stations were installed
in Peru, Bolivia, and Chile.
Short-period vertical seismograph designed by DTM for use in South American seismic network. Data could be recorded for up to one week without intervention.
DTM-built horizontal-motion seismometer used in South American seismic network.
South American scientists at DTM for a 2-month long intensive seminar determine earthquake epicenters
using a “ping-pong table” analog computer.
First broad-band, large dynamic range seismometer designed at DTM by Selwyn Sacks.
Alan Linde, Selwyn Sacks, and Shigeji Suyehiro search for seismic events on DTM broadband seismograph tapes.
Selwyn Sacks, Shigeji Suyehiro, and Michael Seemann assemble a borehole strainmeter – a device developed by Sacks and Dale
Evertson for measuring minute deformation in the Earth.
Installing DTM borehole strainmeters at Matsushiro Observatory, Japan (1971) and 3.2 km underground
in a South African gold mine (1978).
Strain record of a “slow” earthquake sequence in Japan – undetectable with seismometers but recorded
by DTM borehole strainmeters (Alan Linde et al.)
DTM’s Paul Silver (shown here in Bolivia) and colleagues pioneered the deployment of modern, portable
broadband seismic arrays.
South Africa 1998
South Africa 1997
Broadband seismometer installations around the world by DTM scientists and collaborators.
Mantle plume beneath Iceland imaged by seismic tomography from the ICEMELT experiment (Cecily Wolfe et al.)
“Huddle test” of 40 three-component broadband seismometers in DTM testing facility (Rod Green,
Randy Kuehnel, Adriana Kuehnel)
1800-km long seismic array for study of the deep structure of the Kaapvaal Craton in southern Africa
(David James, Paul Silver, et al.)
Diana Roman deploys a BENTO2 seismic-monitoring box at Hekla Volcano, Iceland. Satellite telemetry enables continuous monitoring of volcanoes in remote areas.
Lara Wagner with a Carnegie Quick Deploy Box (QDB) – a new, portable broadband seismometer small and light
enough to be checked as airline luggage.
DTM field seismologist Steven Golden tests a new broadband seismometer for array deployment on Vanuatu.