Over the past few months, GMS has participated in reconnaissance after the sequence of Magnitude M5.2 and M5.7 earthquakes that occurred in the Ionian Island of Cephalonia earlier this year. The Geotechnical Extreme Events Reconnaissance Association has released the report of its findings.
GEER members and other earthquake professionals documented the earthquakes’ effects on the subsurface and infrastructure of the region. The GEER team focused on documenting geotechnical effects of extreme events as part of the U.S. National Earthquake Hazards Reduction Program (NEHRP). Advancing earthquake-resistant design requires that many disciplines work together to understand what happened during such earthquakes. GEER collaborated with the Learning from Earthquakes Program of the Earthquake Engineering Research Institute (EERI), and the Applied Technology Council (ATC), represented by Ramon Gilsanz of Gilsanz Murray Steficek (GMS), a board member of the EERI-NYNE Chapter and past president of ATC, as well as with EERI members in Greece.
The Cephalonia, Greece Earthquakes occurred on the Ionian Island of Cephalonia which is situated on the subduction of the African and European plates and has historic large seismicity. The sequence of the 2014 M5.2 and M5.7 earthquakes a week apart, revived memories of the 1953 earthquakes that occurred in the same region and produced extensive damage on the island with two events of M6.4 and M7.2, occurring 3 days apart. The 2014 earthquakes were felt over a widespread area, including the capital, Athens. A particular focus of the GEER study will be observations of performance of waterfront structures, ports and quay walls, liquefaction and lateral spreading, slope stability, near-fault motions, topographic effects of the ground motions, and soil-foundation interaction. It will be important to study how soil and geologic conditions may have influenced structural and non-structural damage patterns in the region.
Extreme events engineering is an experience-driven field where immediately following the occurrence of an event (e.g., earthquake, tsunami, hurricane, landslide, or flood), perishable data that can be used to advance our understanding is systematically collected. Field observations are particularly important in the field of geotechnical engineering, because it is difficult to replicate in the laboratory soil deposits built by nature over thousands of years. Detailed mapping and surveying of damaged areas provides the data for well-documented case histories that drive the development of many of the design procedures used by engineers. Documenting and sharing the key lessons learned from major events around the world contributes significantly to advancing research and practice in engineering. Working collaboratively with other organizations in reconnaissance, such as local universities, EERI and ATC, enrich these key lessons.