Scilly Isles, UK: optical dating of a possible tsunami deposit from the 1755 Lisbon earthquake

2001 ◽  
Vol 20 (5-9) ◽  
pp. 715-718 ◽  
Author(s):  
D. Banerjee ◽  
A.S. Murray ◽  
I.D.L. Foster
Author(s):  
Valérie Clouard ◽  
Jean Roger ◽  
Emmanuel Moizan

Abstract. In order to assess tsunami hazard in oceanic islands, one needs to enlarge the observational time window by finding more evidence of past events. To that end, evidence of allochthonous deposits provides estimates of tsunami inundation, recurrence time and magnitude. However, in tropical islands, erosion due to the highly rainy climate generally prevents deposits to stay in place and when they are, relating them to a tsunami is not straightforward, as they can result either from a strong hurricane or from a tsunami. One notable exception concerns deposits sealed by subsequent events. In this paper, we present evidence of an anomalously thick two-layer tsunami deposit in an excavation in Martinique. Analysis of the archaeological remains indicate that it is related to the 1755 Lisbon tsunami. We explain the thickness of the deposit by a tsunami-induced bore in the mangrove drainage channels of Fort-de-France. Our results highlight the benefits of collaborative research involving geology and archaeology, indicate a way to improve our tsunami databases and further constrain the use of numerical modelling to predict paleo-tsunami deposit thickness.


Geosciences ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 257 ◽  
Author(s):  
Mihaela Tudor ◽  
Ana Ramos-Pereira ◽  
Pedro J.M. Costa

The CE 1755 Lisbon tsunami was the largest historical tsunami to affect the Atlantic coasts of Europe and North Africa. This study presents the results obtained from the application of different sedimentological techniques (e.g., grain size, morphoscopy, microtextural analysis, geochemistry, radiocarbon dating) on sediments retrieved from the Alcabrichel River alluvial plain (of about 500 m far away from its mouth and approximatively 50 km northwest of Lisbon, Portugal). The results allowed the identification of a sandy layer that was associated with the CE 1755 tsunami. Furthermore, a new microtextural semi-quantitative classification was applied to enhance the identification of extreme marine inundation deposits. Based on sedimentological data, three different tsunami inundation phases were identified, including two inundations and a likely backwash. This innovative work offers physical evidence of the spatial presence of the CE 1755 tsunami event on the western coast of Europe. It also enables a reconstruction of tsunami inundation dynamics, with two flooding waves and an interspersed backwash.


2021 ◽  
Vol 64 ◽  
pp. 101182
Author(s):  
Kieran O'Gorman ◽  
Dominique Tanner ◽  
Mariana Sontag-González ◽  
Bo Li ◽  
Frank Brink ◽  
...  

2016 ◽  
Vol 334 ◽  
pp. 21-33 ◽  
Author(s):  
J. Cascalho ◽  
P. Costa ◽  
S. Dawson ◽  
F. Milne ◽  
A. Rocha

2005 ◽  
Vol 26 (2) ◽  
pp. 283-297 ◽  
Author(s):  
Roberto A. Scasso ◽  
Andrea Concheyro ◽  
Wolfgang Kiessling ◽  
Martin Aberhan ◽  
Lutz Hecht ◽  
...  

2014 ◽  
Vol 104 (5) ◽  
pp. 2149-2161 ◽  
Author(s):  
M. A. Baptista ◽  
J. M. Miranda ◽  
J. Batllo

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