Multi-stage volcanic island flank collapses with coeval explosive caldera-forming eruptions

Area of Science:

• Volcanology
• Geology
• Earth Science

Background:

• Volcanic flank collapses and explosive eruptions are major destructive geological processes.
• Terrestrial flank collapses, like Mount St. Helens, can precede eruptions, while island flank collapses can be larger and multistage.

Purpose of the Study:

• To investigate the relationship between multistage landslides and caldera-forming explosive eruptions on Tenerife.
• To determine which stages of flank collapse trigger explosive volcanic events.

Main Methods:

• Geochemical analysis of volcanic glasses from marine turbidites associated with landslide stages.
• Correlation of landslide stages with coeval explosive eruption deposits.

Main Results:

• Only the final subaerial stages of multistage landslides contained materials from coeval explosive eruptions.
• Initial, more voluminous submarine landslide stages appear to trigger the subsequent explosive caldera-forming eruptions.
• Significant time lags exist between landslide stages and between initial collapse and subsequent eruption.

Conclusions:

• Multistage landslides on volcanic islands, particularly their initial submarine phases, can induce explosive caldera-forming eruptions.
• The time lag following landslide-induced decompression impacts magmatic system responses.
• Findings have implications for understanding ocean island volcanism and civil emergency planning.