We are told that when SR111 hit the water "seismographic recorders in Halifax and in Moncton recorded a seismic event".
Does anyone have the expertise to confirm that, and to say whether the same could be expected of any large aircraft hitting the ocean (intact I presume)?
Don't know the answer there, but I do know there have been many more tsunami warning seismographic recorders installed since the 2004 tsunami, all over the SE Asian region ...