Paleotsunamis from the central Kuril Islands segment of the Japan-Kuril-Kamchatka subduction zone

Abstract

Paleotsunami records from the central Kuril Island segment of the Japan-Kuril-Kamchatka subduction zone indicate that the region has been frequently inundated by tsunamis. As many as 20e22 tsunami deposits are recognized on Matua Island for the past 3300 yr with an average tsunami recurrence interval of ~150 yr, and 34e36 tsunami deposits are evident on Simushir Island for the past 2350 yr with an average recurrence of ~65 yr. These intervals are short, but comparable to other segments of the Japan-Kuril-Kamchatka subduction zone. Results from all survey locations reveal shortening recurrence intervals toward the present, especially for the last 600 yr, indicating a possible preservation bias. On Simushir, tsunamis at least 11 m higher than the modern tsunamis in 2006 and 2007 occurred every ~300 yr on average. On Matua, tsunamis with slightly farther inundation than the 2006 and 2007 tsunamis occurred every ~215 yr while those with at least 100 m farther inland inundation occur every ~750 yr. Our paleotsunami record almost certainly includes tsunamis that are not from great subduction zone earthquakes in the central Kuril segment: we expect the Matua record includes volcanic tsunamis and the Simushir record includes tsunamis from the southern Kuril segment.

The 1997 Kronotsky earthquake and tsunami and their predecessors, Kamchatka, Russia

“…While we cannot typically reconstruct profiles that have been changed by erosion, we can reconstruct profile progradation (building seaward), which affects profile width. Our method uses preserved tephra as discussed, for example, in Pinegina et al (2013) and MacInnes et al (2016), as summarized in Fig. S5.…”

Supplementary material to "1997 Kronotsky earthquake and tsunami and their predecessors, Kamchatka, Russia"

“…Ideally, a reconstruction of the prehistoric coast and hence of paleotsunami size (runup and inundation as approximated by deposit extent) will include an estimate of horizontal shifts of shoreline location for paleoinundation and an approximation of change in relative sea level for paleo-runup. We use tephra stratigraphy (as in Pinegina et al, 2013;MacInnes et al, 2016) and tephra mapping along profiles in order to reconstruct paleoprofiles. The reconstruction of the south Kamchatsky Bay profiles and their paleotsunamis was first performed and reported by Pinegina (2014).…”

Coastal erosion and recovery from a Cascadia subduction zone earthquake and tsunami

“…These events have renewed efforts to understand the impacts and frequency of past tsunamis on coastlines. New studies have improved our ability to identify their deposits in the sedimentary record (Gelfenbaum and Jaffe, 2003;Switzer et al, 2006;Morton et al, 2007;Gouramanis et al, 2015) and determine the inland extents and frequencies of past tsunamis across the globe (Kelsey et al, 2002;Schlichting and Peterson, 2006;MacInnes et al, 2016). However, despite these advances, identifying past tsunami deposits in areas marked by sandy shorelines without muddy or peaty backbarrier deposits remains difficult.…”