Seismic ocean thermometry

Abstract

Hearing the heat Most of the excess heat that causes global warming is absorbed by the oceans. Quantifying that heat increase is challenging because it requires many different temperature measurements over both the vertical and horizontal extent of the oceans. Wu et al. report success in this effort through the use of a different method: They inferred temperature changes from sound waves generated by repeating earthquakes (see the Perspective by Wunsch). The travel time of these earthquakes from source to receiver reflects changes in the average water temperature that they encounter. This technique should substantially enhance our ability to monitor ocean warming. Science , this issue p. 1510 ; see also p. 1433