About the Cover

Using GPS observations and accelerometer data, researchers evaluated the deflection of a large suspension bridge that connects Brooklyn with Staten Island at the mouth of upper New York Bay under the load of New York City Marathon runners (shown on the cover) and under the load of vehicles. They found that runners caused the bridge to vibrate quite differently than vehicles, and that their results can help predict a bridge’s response to very-long-wavelength disturbances that might arise during earthquakes. The article, “Load Response on a Large Suspension Bridge during the NYC Marathon Revealed by GPS and Accelerometers,” by Mikhail G. Kogan, Won-Young Kim, Yehuda Bock, and Andrew W. Smyth, begins on page 12. Photo by Vincent Laforet/The New York Times/Redux. Reproduced with permission.