Using Crustal Deformation

measurements to gauge future earthquakes

Cascadia Hazards Institute

Dept. of Geological Sciences

Central Washington University

www.cascadiahazards.org

Timothy I. Melbourne

Crustal Deformation & Earthquakes1. Cascadia Subduction Zone

2. Measuring how Earth’s surface deforms (crustal deformation)

3. A lesson from Japan

4. Computer simulation of a Magnitude-9 Cascadia earthquake

Seattle (4m)

Vancouver (3m)

Rex FlakeAndrew MinerMarcelo SantillanCraig ScrivnerWalter Szeliga

Aaron MayfieldRodger WilsonAna AguiarJames ChapmanIvan Rabak

Megan KostickRosie StahlKyle KinkadeWendy StockwellSergio Abundiz

CascadiaMag-9

earthquake in themaking

Test 1: comparison with current interseismic deformation:

A rough forecast of future slip after full recurrence interval

GPS stations with ~10 years of measurements

Data from Leonard et al, 2004

ETS-delineated coupling model: Replicates gross distribution of paleoseismic subsidence

GPS stations with ~10 years of measurements

Japan’s GEONET GPS ARRAY (1995)

March 11 M9.0 Tohoku Earthquake

2011 Tohoku-Oki 3d GPS displacements (3x speed)

WA coastal communities move ~75’ and subside ~10’