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

Abstract

Evidence for frequent, large landslides on the flanks of the volcanic edifices forming the Canary Islands include outstanding landslide scars and their correlative submarine and subaerial rock and debris avalanche deposits. These landslides involved volumes ranging from tens to hundreds of km3. The sudden entry of large volumes of rock masses in the sea may have triggered tsunamis capable of affecting the source and neighboring islands, with the resulting huge waves dragging coastal and seabed materials and fauna and redepositing them inland. Here, we present new geological evidence and geochronological data of at least five megatsunamis in Tenerife, Lanzarote, and Gran Canaria, triggered by island flank megalandslides, and occasionally explosive eruptions, during the last 1 million years. The exceptional preservation of the megatsunami deposits and the large area they cover, particularly in Tenerife, provide fundamental data on the number of tsunami events and run-ups, and allow proposals on the sources and age of the tsunamis. Tsunami run-up heights up to 290 m above coeval sea level, some of the highest known on Earth in recent geological times, were estimated based on sedimentological, geomorphological, paleontological, and geochronological data. The research results made it possible to estimate the recurrence of tsunamis in the archipelago during the last hundreds of thousands of years, and to establish relationships between tsunami deposits and the probable triggering island flank landslides.

The sensitivity level of landslide risk using Geographic Information System on the slopes of Mount Argopura, East Java, Indonesia

“…Jember is surrounded and bounded by plateaus such as Mount Argopura, Mount Ijen, Mount Raung, and the southern karst mountains (Basuki et al, 2022;Soetriono et al, 2023). Regarding geomorphology, these conditions form watershed and catchment areas Ferrer et al, 2021;Geitner et al, 2021;Basuki et al, 2022). The air intake area is an air absorption area by infiltration from rain and is stored in the soil pores (Jourgholami et al, 2021;Stuurop et al, 2022).…”

“…When catching damaged water, the runoff is higher than the infiltration, resulting in increased surface runoff and the ability to carry more considerable material through it (Suprayogo et al, 2020;Sugianto et al, 2022). This condition will cause floods and landslides (Ahmad et al, 2018;Ferrer et al, 2021;Geitner et al, 2021).…”