April 2016 Ecuador Earthquake of Moment Magnitude M<sub>w</sub>7.8: Overview and Damage Report

Abstract

The northern coastal region of Ecuador was affected by a moment magnitude Mw7.8 strong earthquake on April 16, 2016, with a recorded PGA of 1.41 g close to the epicenter. The earthquake was named “Pedernales” because the epicenter was near this small town located in the coastal province of Manabí, with a hypocentral depth of 21 km. Two strong aftershocks of Mw6.7 and Mw6.9 were felt a month later and they continued the destruction caused by the main event. Ecuador is located in a seismic zone with a long history of major earthquakes that have caused a lot of destruction in the last six centuries, the main seismic source comes from the subduction of the Nazca Plate under the South American Plate, but there are also crustal earthquakes and volcanism on the Andes Mountains that cross the country from north to south. In the northern coastal province of Esmeraldas a powerful earthquake of moment magnitude Mw8.8 was recorded in 1906, with a rupture area that has caused strong earthquakes in the 20th and 21st centuries. This paper describes the seismological aspects and the recorded strong ground motions, the geotechnical and infrastructure performance, site amplification and liquefaction on a few places, structural damage and collapse of buildings, extensive non-structural damage (mainly large damage to masonry walls) at high-rise buildings in cities near (100 km) and far away (270 km) from the epicenter, due to local soil conditions and flexible framed reinforced concrete structures.