activation of splay faults rupturing in sedimentary prisms (Sanriku, Japan; Kurils),⁵ or rupture propagating in a jagged mode along poorly coupled interfaces in sediment-starved environments (Nicaragua, Peru).⁶ In turn, this raises the questions whether any subduction zone can be the site of a tsunami earthquake, and conversely whether the documented occurrence of such events (most often comparatively small in the magnitude 7.5 range) precludes the occurrence of mega-earthquakes as would be suggested by the available historical record in Nicaragua or Java. Despite active research efforts in this domain, we presently have no firm answers in this respect.

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