Geotechnical reconnaissance findings of the October 30 2020, Mw7.0 Samos Island (Aegean Sea) earthquake

Abstract On October 30, 2020 14:51 (UTC), a moment magnitude (M w ) of 7.0 (USGS, EMSC) earthquake occurred in the Aegean Sea north island Samos, Greece. Turkish and Hellenic geotechnical reconnaissance teams were deployed immediately after event their findings are documented herein. The predominantly observed failure mechanism was that earthquake-induced liquefaction its associated impacts. Such failures presented discussed together with preliminary assessment performance building foundations, slopes deep excavations, retaining structures quay walls. Anatolian side (Turkey), exception Izmir-Bayrakli region where significant site effects observed, no major form foundation failures, surface manifestation lateral soil spreading, rock falls/landslides, structures, walls, subway tunnels. In Samos (Greece), evidence liquefaction, spreading damage to walls ports on northern island. Despite proximity fault (about 10 km), amplitude duration shaking, phenomena not pervasive. It is further unclear whether due underlying soil, or merely inertia those conjunction presence soft (yet necessarily liquefied) soil. A number rockfalls/landslides but relevant particularly severe. Similar side, engineered infrastructure such as dams, bridges, viaducts, tunnels which can be mostly attributed lack infrastructure.