Forums   |   Events   |   Careers   |   Sign In   |   Join AEG
Community Search


DC-Maryland-Virginia Chapter Meeting
Tell a Friend About This EventTell a Friend

When: October 19, 2017
5:30 PM
Where: Amphora Restaurant
377 Maple Ave W
Vienna, Virginia  22180
United States
Contact: Cheryl Gannon

« Go to Upcoming Event List  

Thursday, October 19, 2017

Topic: Amplification of earthquake ground motions by Atlantic Coastal Plain sediments: Implications for Central and Eastern U.S. seismic hazards

Presenter: Thomas Pratt, PhD, Research Geophysicist, U.S. Geological Survey

Location: Amphora Restaurant, 377 Maple Ave W, Vienna, VA 22180

Please click here to view the meeting announcement for full details (61 KB).

Please reserve a seat by Monday, October 16!

Two options for RSVP:
1) Reply to Cheryl Gannon and plan to pay in person (check or cash) at the meeting, or
2) Use the AEG-DMV PayPal button below to RVSP and pay online.


Damage in Washington, DC, during the 2011 Mw5.8 Mineral, VA, earthquake was surprisingly high for an epicenter 130 km away, and "Did-You-Feel-it" felt reports suggest that ground motions in the city were amplified by Atlantic Coastal Plain and other unconsolidated deposits. Thicker Atlantic Coastal Plain and Mississippi Embayment strata throughout the central and eastern US produce strong fundamental resonance peaks in the 0.2 to 4 Hz frequency range on spectral ratios computed from crustal-scale seismic experiments. These spectral ratios can be converted from frequency to depth, resulting in depth-converted spectral ratios across the array that produce an image of the strata causing the resonances. The data sets thus provide an average velocity function for the sedimentary sequence, the frequencies and amplitudes of the major resonance peaks, and a subsurface image of the major reflectors producing resonance peaks, and show that teleseismic signals can be used to characterize sedimentary strata in the upper km.

Dr. Thomas Pratt is a research geophysicist at the US Geological Survey's Geologic Hazards Science Center within the Earthquake Hazards program. Dr. Pratt serves as Editor-in-Cheif of the Bulletin of the Seismological Society of America, which is one of the premier scientific journals for earthquake science. He received his bachelor's degree in geology at Cornell University in 1980, and his master's (1982) and doctorate (1986) degrees in geophysics at Virginia Tech.

Sign In


8/2/2018 » 8/2/2019
AEG Carolinas Summer Meeting

8/7/2018 » 8/9/2018
GeoHazards Impacting Transportation in Appalachia

AEG at The Muny – Meet Me in St. Louis & Backstage Tour

Nashville Chapter Dinner Meeting & Speaker at Bavarian Bierhaus

Annual Meeting

  September 15-23, 2018  
61st AEG Annual Meeting
13th IAEG Congress
  Hyatt Regency San Francisco
San Francisco, California