Missouri Geological Survey

Joe Gillman

The Central U.S. is Earthquake Country: The Science Behind EarthquakesHazard PreparednessResponse

Stress accumulation along plate boundaries from tectonic activity, most earthquakes occur at or near plate boundaries.

Plate Boundaries and Earthquakes

Earthquakes also occur in other regions not associated with plate boundaries. These are intraplate quakes. New Madrid Seismic Zone

Plate Boundaries and Earthquakes

Effects of Shaking: Geology Matters

Effects of Shaking: Geology Matters

Shaking intensity varies from area to area depending on the underlying geology. Thicker, soft sediments can amplify earthquake waves.

Floodplain

Bedrock

Soft sediment

amplification analogy:

Jell-O

Effects of Shaking:

Liquefaction, lateral spreading, sinkholes, landslides, ground fissures, groundwater disturbance.

Effects of Shaking:

Liquefaction, lateral spreading, sinkholes, landslides, ground fissures, groundwater disturbance.

Effects of Shaking:

Liquefaction, lateral spreading, sinkholes, landslides, ground fissures, groundwater disturbance.

Effects of Shaking:

Liquefaction, lateral spreading, sinkholes, landslides, ground fissures, groundwater disturbance.

Danger in the Central US: Regional Perspective

Colors show levels of horizontal shaking that have a 2-in-100 (2%) chance of being exceeded in a 50-year period. Shaking is expressed as a percentage of g (gravitational force).

Danger in the Central US: New Madrid Seismic ZoneActivity

1811-1812 Event

Recurrence Interval

Annual Activity

Probability

USGS Fact Sheet 2009–3071

What is the most likely earthquake we can expect today, not in 500 or

1000 years, but today?

Recurrence Intervals for New Madrid Earthquake Events

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Impact of a M6.5 earthquake

Unreinforced Masonry construction (URM)

• 500,000 URMs in New Madrid region

• FEMA estimates 90% of casualties from URMs

Integration of geologic and geotechnical data into hazards planning

Integration of geologic and geotechnical data into hazards planning

• Bedrock characteristics• Surficial materials characteristics• Depth to water table• Slope stability

What does geologic characterization have to do with earthquake planning and preparedness?

• Damage prediction

• Emergency route planning

• Construction standards

• Emergency facility placement

• Loss estimation

Post Earthquake Technical Information Clearinghouse

-PETIC-

• Use of science information by EMAs requires interpretation and integration with those operations

• Critical need to document geologic and engineering effects of earthquakes by geologists and engineers

• Relieves overburdened EMA officials from the task of managing “science” requests

Purpose

• Facilitating coherent and methodical investigations of the physical impact of an earthquake

• Collection and assimilation of perishable data

• Single POC for exchange of information between EMs and scientific investigators

•Scientist pool

•Long term data management and archive

Objectives

Function of MGS Earthquake Response Plan

Activation:

• M >4.5 when damage is caused• At the request of SEMA/Public Safety

• Should be operational within 24 hours• Duration will be event dependent

• Located at MGS in Rolla with forward operations established as practical

Missouri PETIC

Additional Information

• Missouri Geological Survey – http://www.dnr.mo.gov/geology

• Central United States Earthquake Consortium - http://www.cusec.org/