Next Article in Journal
The Unique Granite Gorge in Mountainous Adygeya, Russia: Evidence of Big and Complex Geosite Disproportions
Previous Article in Journal
Coseismic Ground Deformation Reproduced through Numerical Modeling: A Parameter Sensitivity Analysis
Previous Article in Special Issue
Post Seismic Catalog Incompleteness and Aftershock Forecasting
Open AccessArticle

Landslides Triggered by the 2016 Mw 7.8 Pedernales, Ecuador Earthquake: Correlations with ESI-07 Intensity, Lithology, Slope and PGA-h

1
Facultad de Ciencias Matemáticas, Físicas y Químicas, Carrera de Ingeniería Civil, Universidad Técnica de Manabí (UTM), Avenue José María Urbina, Portoviejo 130111, Ecuador
2
Facultad de Ciencias de la Ingeniería, Universidad Estatal Península de Santa Elena, Km 1 vía principal, La Libertad 240350, Ecuador
3
Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell’Insubria, Via Valleggio 11, 22100 Como, Italy
4
Grupo de Investigación en Geociencias Marinas y Costeras (GEMAC-FIMCM-FICT), Escuela Superior Politécnica del Litoral, Campus Gustavo Galindo, Km 30.5 vía Perimetral, Guayaquil 09015863, Ecuador
5
Facultad de Ciencias Naturales, Universidad de Guayaquil, Av. Raúl Gómez Lince s/n y Av. Juan Tanca Marengo, Guayaquil 090150, Ecuador
*
Author to whom correspondence should be addressed.
Geosciences 2019, 9(9), 371; https://doi.org/10.3390/geosciences9090371
Received: 9 August 2019 / Accepted: 19 August 2019 / Published: 26 August 2019
We provide a dataset of the landslides induced by the 2016 Pedernales megathrust earthquake, Ecuador (Mw 7.8, focal depth of 20 km) and compare their spatial distribution with mapped bedrock lithology, horizontal peak ground acceleration (PGA-h) and the macroseismic intensity based on earthquake-induced environmental effects (ESI-07). We studied 192 coseismic landslides (classified as coherent, disrupted and lateral spreads) located in the epicentral area, defined by the VII to IXESI-07 isoseismals. Based on our findings, lahar deposits, tuffs and volcanoclastic units are the most susceptible to landslides occurrence. Alluvial plains with fluvial loose fine sand are the most susceptible setting for lateral spreading, with a maximum intensity of IXESI-07. The coherent landslides are frequently found in altered shale and siltstone geological units with moderate slopes (8°–16°), with typical intensity ranging between VII and VIIIESI-07. Our analysis draws a typical framework for slope movements triggered by subduction earthquakes in Ecuador. The most dangerous setting is the coastal region, a relatively highly urbanized area located near the epicenter and where liquefaction can trigger massive lateral spreading events. Coherent and disrupted landslides, dominating the more internal hilly region, can be triggered also in moderate slope settings (i.e., less than 10°). Indeed, the regression analysis between seismic intensity, PGA-h and landslide occurrence shows that most of the events occurred at PGA-h values between 0.4 g and 1.2 g, at a distance of 30 to 50 km from the rupture plane. Our database suggests that lithology and hillslope geometry are the main geological/geomorphological factors controlling coseismic landslides occurrence; while the distance from the rupture plane plays a significant role on determining the landslide size. Finally, we underline that coseismically-triggered landslides are among the most common environmental effects occurring during large subduction events that can be effectively used to properly evaluate the earthquake macroseismic field. The landslide inventory we compiled is suitable for assessing the vulnerability of physical environment from subduction earthquakes in Ecuador, and offers a primary data source for future worldwide analysis. View Full-Text
Keywords: coseismic landslides; macroseismic intensity; ESI-07 scale; Pedernales earthquake; Ecuador coseismic landslides; macroseismic intensity; ESI-07 scale; Pedernales earthquake; Ecuador
Show Figures

Figure 1

MDPI and ACS Style

Chunga, K.; Livio, F.A.; Martillo, C.; Lara-Saavedra, H.; Ferrario, M.F.; Zevallos, I.; Michetti, A.M. Landslides Triggered by the 2016 Mw 7.8 Pedernales, Ecuador Earthquake: Correlations with ESI-07 Intensity, Lithology, Slope and PGA-h. Geosciences 2019, 9, 371.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map

1
Back to TopTop