Interview: Bob Dziak

by William Hanshumaker

(Dr. Robert Dziak, a research faculty member with Oregon State University's Cooperative Institute for Marine Resource Studies, was principle investigator for the "Sounds From the Southern Sea" research project).

Bill: Can the pattern of seismic disturbances be used to predict tsunamis?

Bob: Yes it can. As geologists say, the past is the key to understanding the present and the future. By understanding the past, long-term seismic behavior of a fault when can gauge what the behavior of the fault will be now and in the future. If the fault zone has produced large earthquakes and tsunamis in the past, it will again in the future.

Bill: How do the sounds detected from your hydrophones tell you about global climate change?

Bob:The main idea is that when icesheets and icebergs move, they make a lot of sound that can be heard on our instruments in the ocean. If global ocean temperatures are increasing, the warmer ocean water will cause the icesheets and icebergs to break apart, causing an overall increase in sound (noise) in the ocean that we will detect. This overall increase in noise will be separate from ice noise caused by seasonal changes in temperature.

Bill: Can you compare the plate tectonics of Antactica to the Juan deFuca/North America plates?

Bob: They are similar. A portion of the Antarctic plate is subducting beneath the Antarctic Peninsula, resulting in line of volcanoes forming above the plate that rise above sea level. These volcanoes/islands are called the South Shetland Islands, one of the biggest being King George Island where the Antarctic base is located. This subduction also results in the formation of basin behind the volcanoes. In Antarctica, this basin is referred to as the Bransfield Strait and is filled with water. In the Pacific northwest, the small Juan de Fuca plate is subducting beneath North America. The melting of the Juan de Fuca plate as it sinks into the mantle produces a line of volcanoes called the Cascades. A basin has also formed behind the volcanoes in eastern Oregon, but since it formed in continental crust the basin is above sea level. The main differnce between Antarctica and the Pacific Northwest is that the subduction in Antarctica, the plate is consuming *itself*, not one plate sliding beneath another plate. To my knowledge, this is the only place in the world where this is occurring.

Bill: What advice would you give to students who are interested in marine mammals?

Bob: I would give the same advice to all students interested in marine mammals, marine biology, oceanography, and marine geology. That is to study as many introductory classes in math, physics, chemistry, and computer science as you can. If you have a good understanding of the basics of physical and computer science you can go into any field and study any subject you find interesting.

Bill: Where did you go to school?

Bob:I received an associate of science degree from the college of lake county (junior college). I have a bachelor of science degree in geology and mathematics from the University of Illinois, Urbana-Champaign. I have a master's degree in Geophysics from University of Memphis and a PhD in Geosiences from Oreogn State University.

Bill: Why did you decide to study marine mammals?

Bob: Because their vocalizations were ruining my earthquakes records.

Bill: What part of your job you like the most?

Bob:Doing my experiments that help me learn more about how the Earth works.

Next: Bird and cetacean sighting log