But whether earthquake seismic waves, traveling through the ground, can chip away at Antarctica’s ice sheet - the ice piled on top of the continent - remained an unanswered question. Zhigang Peng, a geophysicist at the Georgia Institute of Technology in Atlanta, found the answer by accident while studying effects of the Chile quake in South America. His team was looking for surface waves - shallow seismic waves that travel along the planet’s crust rather than going deeper into the mantle. Surface waves come in two basic types: Love waves, which shake the ground from side to side; and Rayleigh waves, which move in a rolling motion, compressing and expanding the ground as they travel. Both types of surface waves can in turn trigger numerous microearthquakes, called tremor.