Hawaii: Earthquakes, Structure, and Volcanism

Sarah Shapiro

Background: Plate Tectonics

Hot Spots of the World

Hot Spot Track

Pacific Hot Spot Tracks

Hawaii: What a load…

Lithospheric Flexure

Watts and Zhong, 2000

Seismicity of Hawaii (1990-2001)

Volcanic Earthquakes

USGS: Volcanic earthquakes

“Tornillos”

Swarms(new fractures are forming)

Volcanic Tremor – low freq. vibrations (due to moving magma)

Magma Plumbing from Microearthquakes

Ryan et al., 1981

Surface Geology

So why am I talking about all of this?

My Research: GPR

Equipment

We used a Sensors and Software Pulse Ekko 100, which was equipped with 50, 100, and 200 MHz antennae

Targets included: beach sands nearshore lava flows well-developed soil covers lava tubes major fault zones

GPR Basics: Acquisition

GPR surveys on the Big Island of Hawaii, in conjunction with SES Semester in Hawaii program

Reflection Mode

Common Mid Point

GPR Basics: Penetration

Increasing Penetration

Increasing Conductivity

Why does this matter?

The Hilana Fault Issue

Cannon and Burgmann, 2001

Models of Hilina Fault Geometry

Cannon et al., 2001

Morgan et al, 2000

Models of Hilina Fault Geometry

Tsunami Potential

GPS Measured Motion

Courtesy J. Kauahekaua

Pali Uli

Groundwater

3D Lava Stratigraphy

Lava Tubes

Known lava tubes

GPR surveys above known

lava tubes

Sampling lava flows

I cant complain!

In conclusion....