Geo-Resilience By Soil Improvement: Contrasting the Performance of Two Embankments during a Megathrust Mw 7.8 Earthquake

Abstract

The west coast of Ecuador forms the eastern side of the Pacific “ring of fire” along the Nazca tectonic plate boundary (Figure 1). The epicenter of the Ecuador earthquake on April 16, 2016 (Mw 7.8), was in the city of Pedernales in the province of Manabí. According to the United States Geological Survey (USGS), the main event was caused by shallow thrust faulting, at a hypocentral depth of 21 km, on or near the plate boundary between the Nazca and South America plates, where the Nazca subducts beneath the South America plate at a rate of 61 mm/yr. In the first 24 hours, over 135 aftershocks were recorded, with hundreds more in the weeks that followed. Overall, this megathrust earthquake and its aftershocks led to hundreds of fatalities and thousands of injuries, left tens of thousands homeless, and created an economic impact estimated at 3 percent of Ecuador’s gross domestic product.