1994 Bolivian Earthquake Eric Kiser

1994 Bolivian Earthquake Moment Magnitude (Mw): 8.3 Epicenter: 13.84°S and °W Depth: 631km

Outline Rupture Characteristics Comparison with other Deep Earthquakes Tectonics

Silver et al., 1995

Directivity Analysis Silver et al., 1995

30km by 50km Rupture Plane 40s Duration 1.25 km/s Velocity Rupture plane is too large

Other Rupture Properties No Isotropic Component (Okal, 1996) Friction melting (Kanamori et al, 1998) –Efficiency: –Non-Radiated Energy: 1.4x10 18 J –52,000°C Temperature Increase –Slow Rupture Velocity and Large Slip

Differences in the 1994 Bolivia and Tonga Earthquakes Wiens and McGuire, 1995

Tonga Earthquake

Bolivia Earthquake Tinker et al., 1995

Tectonic Setting Kirby et al., 1995

Tectonic Setting Kirby et al., 1995

Tectonic Setting Kirby et al., 1995

Kinks from compression Kinks meet resistance at the lower mantle Slab Thickening

Summary Deepest earthquake ever recorded Rupture extent, no isotropic component, and seismic efficiency have important implications for deep earthquake mechanisms The majority of deep earthquakes may not exhibit these rupture characteristics