Volcanic-Island Lateral Collapses and Their Submarine Deposits

Abstract

part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

The Hidden Giant: How a rift pulse triggered a cascade of sector collapses and voluminous secondary mass‐transport events in the early evolution of Santorini

“…This lateral variation is typical for MTDs and reflects the transition from proximal slumps of granular material into more disintegrated, water‐saturated, cohesive debris flows and turbidity currents in the distal domain (e.g. Bull et al, 2009; Smit & Stemmerik, 2022; Watt et al, 2012, 2019, 2021). This is observed both at the west (Figure 3a) and to the east (Figures 4–6) of Santorini.…”

“…Volcanic sector collapses have been identified in all volcanic settings and their trigger mechanisms range from volcanic intrusions and eruptions, gravitational instabilities, extreme precipitation events, sea-level changes, to earthquakes (Watt et al, 2021). Identifying a specific trigger mechanism is often ambiguous for contemporary sector collapses and becomes even more difficult for an event ~0.7 Myrs ago (Preine et al, 2022).…”

“…These results have important implications for the magnitude of tsunami generation by volcanic island landslides since secondary seafloor sediment failures are likely to be much less tsunamigenic than the proximal, block‐rich, mass flows (Le Friant et al, 2019; Watt et al, 2012). Therefore, the complexities within submarine volcanic landslides must be carefully considered for an accurate assessment of associated hazards (Watt et al, 2021).…”

Spatio-temporal evolution of the Christiana-Santorini-Kolumbo volcanic field, Aegean Sea

“…2D and 3A) is a thick, widespread, and weakly reflective deposit, which has been described by Tsampouraki-Kraounaki and Sakellariou (2018) in the Christiana Basin and interpreted as a volcanoclastic density-flow deposit. The chaotic internal seismic facies, however, also resembles that of debris-avalanche deposits (Watt et al, 2021). Given the distribution in both the Christiana and Anhydros Basins, the source for this deposit must have been located somewhere close to present-day Santorini.…”

Megatsunamis Induced by Volcanic Landslides in the Canary Islands: Age of the Tsunami Deposits and Source Landslides

“…In historical times, the largest volcanic landslides occurred on island arc volcanoes, characterized by rapid failure and tsunami generation, with volumes <3 km 3 (magnitudes significantly smaller than prehistoric events on intraplate volcanic islands, as is the case of Hawaii and the Canary Islands) and a recurrence of~100 years [31]. The most recent and largest landslide occurred in Ritter island (Papua New Guinea) in 1888 involving a volume~2.4 km 3 [32], which generated a tsunami with observed maximum run-up heights of 15 m on nearby shores [33]; this event ranks among the most disastrous volcanic events in Papua New Guinea in modern times and caused more than 1500 casualties [34].…”