Vorsitzende der Sitzung
Session 3 - Volcanoes: Hazards & Benefits
- Nico Augustin
Session 3 - Volcanoes: Hazards & Benefits
- Elodie Lebas
Active venting of hydrothermal fluids has never been directly observed from the Red Sea, one of Earth's youngest ocean basins, despite ample evidence for hydrothermal activity1. Hydrothermal activity along the Red Sea Rift was, so far, only inferred by extinct chimney fields, metalliferous sediments, and a few high-temperature brine pools that are difficult to access. However, hydrothermal...
The submarine Brothers arc volcano ~350 km NE of New Zealand is a unique site for studying active magmatic-hydrothermal ore formation. The volcano is considered volcanically dormant but continuous to degas actively. The edifice is thus host to an active site of porphyry-epithermal mineralization at its younger cone and hydrothermal massive sulfide formation at its caldera floor and walls. In...
To supplement downhole temperature logging and fluid sampling during the IODP Expedition 376 drilling of the Brothers Volcano, four shipboard experiments were devised and also, metals and rubbers used during drilling examined using petrographic microscopy, FESEM-EDX and X-ray diffractometry. Due to short exposure time for fluid inclusions to form; or misplacement in the drill string of...
Tsunamis of volcanic origin are an often-overlooked threat, posing a hazard to the surrounding coastal environments and submarine infrastructure, with sometimes oceanwide consequences. About one-quarter of volcano-related fatalities recorded in recent historic times have been attributed to volcanic tsunamis. Examples include the tsunamis related to the 1883 and 2018 eruptions of Krakatau,...
The lateral collapse of oceanic volcanoes poses a high risk for the population living in coastal areas since the sudden displacement of large amount of material can trigger tsunami waves impacting the surrounding coastlines. One recent example is the lateral collapse of the SW-flank of Anak-Krakatau (Sunda Strait, Indonesia) in December 2018 that generated a tsunami wave impacting the Sunda...
Southeast Asia (SEA) and nearby regions host only three submarine volcanoes (i.e. seamounts) that erupted during the Holocene according to the Global Volcanism Program (GVP). However, if we include GVP submarine volcanoes that erupted from the Pleistocene, and submarine volcanoes detected through satellite-derived and geophysical methods, the number increase significantly (n= 466). With this...
Volcanoes are sources of numerous threats including lava flows, pyroclastic flows, ash dispersal and landslides or sector collapses. In addition to these common volcanic hazards, volcano-induced tsunamis can occur in the marine environment, introducing a major hazard that can affect populations far away from the volcanoes. Tsunami warning systems are not designed to include volcano-generated...
Volcanic island sector collapses produce some of the volumetrically largest mass movements on Earth. They may trigger devastating tsunamis that pose hazards to coastal communities and endanger seafloor installations. Very little is currently known about the interplay between volcanic activity, subsequent mass wasting events, and their specific emplacement processes. This information is needed...
Volcanic Islands are not only the source of volcanic hazards, such as explosive and effusive eruptions and pyroclastic flows, but can also cause significant tsunamis. While lateral collapses and explosions are destructive events, the accompanying earthquakes are often not large enough to be felt or identified by the global seismological network. Thus, volcanogenic tsunamis can arrive at the...
Most economic gold, silver and copper deposits on Earth are associated with volcanic arcs. However, little is known about the petrogenetic processes that control the Au, Ag and Cu sub-arc budget. In particular, the efficiency of the element recycling in subduction zones and the influence of dip, thickness and composition of the subducting plate (slab) on the budget of these elements in arc...
During IODP Expedition 372/375 marine sediments offshore of North Island, New Zealand, were drilled and included intercalated tephra layers of Miocene to Holocene age. The drill sites are located ~250 km downwind (east) of the active Taupõ Volcanic Zone (TVZ), one of largest and most frequently active silicic centers on earth, and also close to the precursory volcanic arc, the Coromandel...
