The ground in the Puget Sound region didn’t just shake during
the magnitude 6.8 Nisqually earthquake, it moved — literally. In
fact, measurements using global positioning system (GPS) data
indicate that in most areas the ground shifted more during the
Feb. 28 quake than it normally does in a year. “Not only that,
but it moved in completely the opposite direction of what we’ve
observed from year to year,” said Anthony Qamar, a University of
Washington research associate professor in Earth and space
sciences and the state seismologist. Qamar works on a project
called PANGA, or Pacific Northwest Geodetic Array, that uses
global positioning information to measure how much the ground in
western Washington and Oregon move each year relative to a fixed
point farther east. PANGA partners include the UW, Central
Washington University, Rensselaer Polytechnic Institute in Troy,
N.Y., Oregon State University, the U.S. Geological Survey, the
U.S. Coast Guard and the Geological Survey of Canada. PANGA’s
measurements have s