I lived my first decade in suburban and rural Iowa but spent most of my teen and adult years in southern California. My degrees are in geology from UC Riverside and Stanford, and I was a professor of geology at Caltech for three decades. From 2008 to 2020, I led creation of the Earth Observatory of Singapore, which focuses on geohazards research throughout Southeast Asia. I probably would have been better suited to a profession in the humanities, but wandered into earth science because it catered to an introversion that stemmed from my being a closeted gay teen. Perhaps my most important research accomplishments are the use of geology to extend the record of large earthquake ruptures beyond the instrumental record (paleoseismology) in California and extending it to include interseismic deformations (paleogeodesy) in Sumatra, geological determination of the first slip rate for an active fault, and discovery of the site of the Australasian meteorite impact under a volcanic field in southern Laos.

Research Interests

For the past few years my research involvement has been mostly in Indonesia and Laos. In Indonesia, I worked with archeologists to identify from thousands of broken sherds along the coastline of Aceh province clear evidence of a devastating tsunami in the late 14th century CE. That predecessor to the great 2004 tsunami destroyed many coastal settlements and initiated a major restructuring of the economy and politics of that part of the Maritime Silk Road in the 15th century CE. We've also uncovered a nearly 8,000 year record of tsunamis in sandy, bouldery deposits in a cave on the Aceh coast. In Laos, I worked with volcanologists, geochemists and geochronologists to establish the site of the meteorite impact that produced the Australasian strewn field about 790,000 years ago. The crater is hidden beneath the Bolaven volcanic field in southern Laos. Now we are pursuing a characterization of that volcanic field and a study of the non-tektite debris that was strewn over the landscape within a few hundred kilometers of the impact site.

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Primary Section

Section 15: Geology

Secondary Section

Section 16: Geophysics