Q: You literally wrote the book on plate tectonics, earthquakes, volcanism, and other fascinating geological phenomena. Your college textbook, Natural Disasters, now in its 9th edition, is one of the most popular textbooks in the field. What originally led to your interest in the field of geology?
A: I became interested in geology because of its thought processes, fusing some of the best of the arts with the sciences, reading the history of the Earth. The artistic thinking weighs multi-variables through space and time to generate hypotheses. Then, scientific thinking tests the viability of the hypotheses. It is thrilling and satisfying to be a geologist.
Q: Your lectures cover wide-ranging geological topics which link together the itinerary, including how plate tectonics shaped the Northwest-Pacific region, as well as the root causes of the high incidence of earthquakes and tsunami in the Northern Pacific. What evidence of these geological phenomena will Smithsonian travelers witness?
A: Results of plate-tectonic actions will be seen as land upwarped above subduction zones, volcanoes built above downgoing oceanic plates, continental fragments that collided and stacked together. We will see active volcanoes that are part of the famous Pacific Ring of Fire, new coastal lands that formed by uplifting of sea floors during mega-earthquakes, tsunami damage from the 2011 magnitude 9.0 earthquake in Japan and the 1964 magnitude 9.2 earthquake in Alaska, and more.
Q: The Aleutian Islands and the North Pacific Ocean are a remnant of the 1,000 mile wide Bering Land Bridge that enabled human migration to the Americas from Asia approximately 30,000 years ago. Can you please lend perspective, both in terms of the land bridge's geological significance and in terms of its impact on the spread of human populations?
A: Our world today has many islands and extensive shallow seas. But during the last glacial advance, global sea level was 425 feet lower, exposing more land, connecting lands. Peoples of the world could easily migrate into lands new to them -- and they did. For example, when Siberia connected to Alaska, people took the opportunity to move, crossing icy land, kayaking along shores, reaching America in successive waves separated in time. As DNA studies progress, our knowledge of the peopling of the Americas is expanding significantly.