Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Stratigraphic evidence of two historical tsunamis on the semi-arid coast of north-central Chile


DePaolis ,  Jessica M.
External Organizations;

Dura ,  Tina
External Organizations;

MacInnes ,  Breanyn
External Organizations;

Ely ,  Lisa L.
External Organizations;

Cisternas ,  Marco
External Organizations;

Carvajal ,  Matías
External Organizations;


Tang,  Hui
4.7 Earth Surface Process Modelling, 4.0 Geosystems, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Fritz ,  Hermann M.
External Organizations;

Mizobe ,  Cyntia
External Organizations;

Wesson ,  Robert L.
External Organizations;

Figueroa ,  Gino
External Organizations;

Brennan ,  Nicole
External Organizations;

Horton ,  Benjamin P.
External Organizations;

Pilarczyk ,  Jessica E.
External Organizations;

Corbett ,  D. Reide
External Organizations;

Gill ,  Benjamin C.
External Organizations;

Weiss ,  Robert
External Organizations;

External Ressource
No external resources are shared
Fulltext (public)

(Publisher version), 5MB

Supplementary Material (public)
There is no public supplementary material available

DePaolis, J. M., Dura, T., MacInnes, B., Ely, L. L., Cisternas, M., Carvajal, M., Tang, H., Fritz, H. M., Mizobe, C., Wesson, R. L., Figueroa, G., Brennan, N., Horton, B. P., Pilarczyk, J. E., Corbett, D. R., Gill, B. C., Weiss, R. (2021): Stratigraphic evidence of two historical tsunamis on the semi-arid coast of north-central Chile. - Quaternary Science Reviews, 266, 107052.

Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5007317
On September 16, 2015, a Mw 8.3 earthquake struck the north-central Chile coast, triggering a tsunami observed along 500 km of coastline, between Huasco (28.5°S) and San Antonio (33.5°S). This tsunami provided a unique opportunity to examine the nature of tsunami deposits in a semi-arid, siliciclastic environment where stratigraphic and sedimentological records of past tsunamis are difficult to distinguish. To improve our ability to identify such evidence, we targeted one of the few low-energy, organic-rich depositional environments in north-central Chile: Pachingo marsh in Tongoy Bay (30.3°S). We found sedimentary evidence of the 2015 and one previous tsunami as tabular sand sheets. Both deposits are composed of poorly to moderately sorted, gray-brown, fine-to medium-grained sand and are distinct from underlying and overlying organic-rich silt. Both sand beds thin (from ∼20 cm to <1 cm) and fine landward, and show normal grading. The older sand bed is thicker and extends over 125 m further inland than the 2015 tsunami deposit. To model the relative size of the tsunamis that deposited each sand bed, we employed tsunami flow inversion. Our results show that the older sand bed was produced by higher flow speeds and depths than those in 2015. Anthropogenic evidence along with 137Cs and 210Pb dating constrains the age of the older tsunami to the last ∼110 years. We suggest that the older sand bed was deposited by the large tsunami in 1922 CE sourced to the north of our study site. This deposit represents the first geologic evidence of a pre-2015 tsunami along the semi-arid north-central Chile coast and highlights the current and continuing tsunami hazard in the region.