1. 70 Years of Seismology at DTM
Shaun Hardy and Louis Brown
Carnegie Institution for Science
Neighborhood Lecture Series
April 25, 2019

2. 1948
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.

3. 1948 Hypothetical crustal structure beneath Washington DC
from DTM’s earliest explosion seismology experiments.

4. 1951
Detonation of depth charge from a Coast Guard cutter in Puget Sound during joint DTM-GL seismic experiment.

5. 1955
Seismic equipment set up on a railroad flatcar during DTM’s seismic expedition to Alaska and Yukon Territory.

6. 1957
Truck with seismic equipment and radio receiver deployed in Peru during the Carnegie Andes Expedition.

7. 1957
Explosion set off in an open-pit copper mine in Peru for Carnegie’s seismological studies of the Andes during the International Geophysical Year.

8. 1960
DTM cooperative seismic network for the study of local earthquakes. Nineteen stations were installed in Peru, Bolivia, and Chile.

9. 1962
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.

10. 1963
DTM-built horizontal-motion seismometer used in South American seismic network.

11. 1963
South American scientists at DTM for a 2-month long intensive seminar determine earthquake epicenters using a “ping-pong table” analog computer.

12. 1966
First broad-band, large dynamic range seismometer designed at DTM by Selwyn Sacks.

13. 1971
Alan Linde, Selwyn Sacks, and Shigeji Suyehiro search for seismic events on DTM broadband seismograph tapes.

14. 1971
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.

15. 1970s
Installing DTM borehole strainmeters at Matsushiro Observatory, Japan (1971) and 3.2 km underground in a South African gold mine (1978).

16. 1978
Strain record of a “slow” earthquake sequence in Japan – undetectable with seismometers but recorded by DTM borehole strainmeters (Alan Linde et al.)

17. 1994
DTM’s Paul Silver (shown here in Bolivia) and colleagues pioneered the deployment of modern, portable broadband seismic arrays.

18. 1990s
South Africa 1997
Iceland 1995
Zimbabwe 1997
South Africa 1998
Galapagos 2000
Brazil 1993
Broadband seismometer installations around the world by DTM scientists and collaborators.

19. 1997
Mantle plume beneath Iceland imaged by seismic tomography from the ICEMELT experiment (Cecily Wolfe et al.)

20. 1997
“Huddle test” of 40 three-component broadband seismometers in DTM testing facility (Rod Green, Randy Kuehnel, Adriana Kuehnel)

21. 1997
1800-km long seismic array for study of the deep structure of the Kaapvaal Craton in southern Africa (David James, Paul Silver, et al.)

22. 2014
Diana Roman deploys a BENTO2 seismic-monitoring box at Hekla Volcano, Iceland. Satellite telemetry enables continuous monitoring of volcanoes in remote areas.

23. 2016
Lara Wagner with a Carnegie Quick Deploy Box (QDB) – a new, portable broadband seismometer small and light enough to be checked as airline luggage.

24. 2019
DTM field seismologist Steven Golden tests a new broadband seismometer for array deployment on Vanuatu.