greg beroza, a professor of geophysics at stanford university in california, has told me earlier about the key things to look out for during earthquakes. we look to see the context of the occurrence, or the tectonic context. in this case, the earthquake occurred off the west coast of japan that s unlike the 2011 earthquake, which occurred on the plate boundary off the opposite coast of japan. earthquakes in this region aren t unheard of, including large earthquakes. some in the past have generated large tsunamis, so we look immediately at things that are relevant to the earthquake response. but of course, we ll be pouring over the data from earthquakes such as this for years. and as more information becomes available, how do you assess the severity of this latest one? are we likely to see aftershocks in the coming days, and more tsunami warnings perhaps? yeah, there will certainly be aftershocks.