Tsunami intensity mapping: applying the integrated Tsunami Intensity Scale (ITIS2012) on Ishinomaki Bay Coast after the mega-tsunami of Tohoku, March 11, 2011

Katerina-Navsika Katsetsiadou, Emmanuel Andreadakis, Efthimis Lekkas — Tue, 24 May 2016 00:00:00 +0000

The study applies the Integrated Tsunami Intensity Scale (ITIS₂₀₁₂) criteria to map the tsunami intensities distribution in the broader Ishinomaki area, for the 9 Mw March 11, 2011 event offshore Tohoku, Japan. Based on reports, satellite imagery and published information, impact data was mapped, intensity values were assigned and thematic impact maps (layers) were created for each of the ITIS₂₀₁₂ six criteria categories. Most of the criteria result in a mosaic of intensities, which is in many cases due to lack of data, depending on the land use. Two methodologies were used to produce the final map. A land-use-based weighted overlay was applied integrating the six layers, resulting in a final map that rather shows damage tsunami assessment on Ishinomaki area. The second final map was produced using the maximum intensity grade throughout the six layers for each pixel. This map showed an excellent zoning filling in any gaps due to information lack in some layers and areas, with maximum intensity data from the others, highlighting the ITIS₂₀₁₂ criteria complementarity and is the tsunami intensity map of the study area.

Time dependent seismicity along the western coast of Canada

Evangelos V. Christou, George Karakaisis, Emmanuel Scordilis — Fri, 15 Apr 2016 00:00:00 +0000

Decelerating generation of intermediate magnitude earthquakes (preshocks) in a narrow region (seismogenic region) and accelerating generation of relatively larger such earthquakes in a broader region (critical region) has been proposed as an appropriate model for intermediate-term earthquake prediction. We examined the seismic activity which preceded the M_w=7.7 (October 28, 2012) thrust event that occurred off the west coast of Haida Gwaii, Canada (formerly the Queen Charlotte islands), by applying the decelerating-accelerating seismic strain model. We found that this mainshock was preceded by a pronounced accelerating seismic sequence with the time to the mainshock, as well as by an equally easily identifiable decelerating seismic sequence. Both precursory seismic sequences occurred in different space, time and magnitude windows. The behavior of previous mainshocks that occurred close to the 2012 earthquake was also examined by the time and magnitude predictable regional model. An attempt was also made to identify such seismic strain patterns, which may also be related to the generation of strong mainshocks along the western coast of Canada.

Research in Geophysics

Tsunami intensity mapping: applying the integrated Tsunami Intensity Scale (ITIS2012) on Ishinomaki Bay Coast after the mega-tsunami of Tohoku, March 11, 2011

Time dependent seismicity along the western coast of Canada