Unger's career blessed with a shakey start
March 11, 2003
Tracking earthquake motion with a seismograph
Perhaps the most emblematic device in geophysics, the seismograph records the intensity and duration of earthquakes and other earth tremors. Most seismographs employ suspended weights that, when the earth shakes, scarcely move due to their inertia. But those slight movements are transmitted to a marker that leaves a record on paper drawn across a drum. The result is the classic analog signature of an earthquake. Modern seismographs are more compact, capture data digitally and, typically, are networked for real-time data transfer. In the future, seismographs may consist of a single computer chip plugged into an ethernet. The seismograph pictured here is a custom-built portable model UW-Madison seismologists used to record seismic activity in remote places.
Tracking plate motion and fault slip with global positioning
GPS technology uses radio signals from satellites to mark positions on the Earth's surface with great accuracy. State-of-the-art GPS equipment is capable of fixing the latitude, longitude and height of any spot on the planet to within 5 millimeters (0.2 inch), after 24 hours of measurements. Repeat GPS measurements at a site for months or years allow geoscientists to measure plate motion, and to study faults and earthquake hazards. Here, a UW-Madison GPS antenna is at work in Mexico with Volcan Fuego de Colima as a backdrop.
Story photos:
Bill Unger (first story photo, right), research program manager for the department of geology and geophysics, years ago prepares to ignite 800 pounds of explosives from a boat in the Pacific Ocean off the coast of Buenaventura, Columbia, as part of seismology research. Photo courtesy of Bill Unger, Department of Geology and Geophysics
Chuck DeMets (second story photo, right), professor of geology and geophysics, and Bill Unger, research program manager in the Department of Geology and Geophysics, discuss DeMets' recent site-finding trip to Mexico. DeMets holds a GPS antenna and spike mount. Photo: Michael Forster Rothbart
The faded black-and-white snapshot of a scruffy-haired young man could have come from any family photo album.
The image shows the man nosing up to a set of 55-gallon drums lashed tightly together, perhaps a backyard project or the makings of a homemade raft soon to be launched on a northern-Wisconsin lake.
But in fact, the man in the picture was preparing to light the fuse on an 800-pound bomb that years ago was tipped over the stern of a rickety boat in some distant corner of the world and detonated below the surface.
The resulting explosion sent a powerful shock wave downward through the earth. This created a seismic signal that, captured by a network of portable seismographs, painted a picture of the earth's deep, hidden structures.
This vintage photograph shows an early "shot" in the long career of Bill Unger, a research program manager in the UW-Madison Department of Geology and Geophysics. Beneath that pedestrian title is a career that spans four decades and all the world's continents. With exotic stops and unusual work on the itinerary, Unger's work has had an Indiana Jones-like quality.
His career has taken him to the Ross Ice Shelf in Antarctica, to Kenya's Great Rift Valley and to Siberia's Lake Baikal. A couple times a year, a few weeks at a time, Unger would work the logistical magic that permits science to happen in unusual places
In the old days, caravans of as many as 10 trucks, organized by Unger and his faculty partners, would weave across African or South American landscapes, hauling tons of equipment for vital experiments.
His faculty partners — the late, legendary seismologist Robert Meyer and internationally renowned glaciologist Charles Bentley — included their staffs in all aspects of a study, from setting off explosions or "shots," to building equipment, to analyzing data, to cleaning up the department garage. Unger's name even appears on a few scientific papers.
Unger also no longer does "shots." Technology and environmental laws, not to mention concerns about transporting explosive materials over international borders, have overtaken the practice of seismologists creating their own shock waves. Instead of setting up a portable seismograph and camouflaging it to keep it safe from thieves in the bush, Unger now installs simple steel pins in the ground along a fault, noting their precise locations so, in a year, he can return and develop information about the waltz of tectonic plates.
In the geology department, Unger is known not only for his skill, versatility and dedication to the work at hand, but for the karma he brings to a project.
"We're starting to call him earthquake man," says Charles DeMets, a faculty member who, with Unger, rode out a whopper of an earthquake in Mexico in January. The earthquake was Unger's second firsthand experience with a sizable seismic event, unusual for anyone who spends the bulk of his time in a geologically stable place like Wisconsin.
"I like the challenge of setting up equipment and getting it operating," says Unger. "The other challenge is getting along in a different culture."
For his UW-Madison geoscientist colleagues, these challenges will have to be met some day without the calming and steady influence of a man who's made difficult fieldwork look like a breezy adventure. They can only hope Unger leaves his seismic karma behind.