Vorsitzende der Sitzung
Session 4 - Submarine Volcanism
- Philipp Brandl
Session 4 - Submarine Volcanism
- Morelia Urlaub (GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany)
Session 4 - Submarine Volcanism
- Philipp Brandl
Since its pumice raft captured the world’s attention in 2012, Havre has become a natural laboratory to research submarine volcanism. In the decade since its eruption, Havre’s eruptive style has been proposed, volcaniclastics dispersal modelled, and eruption products analysed. However, subsurface stratigraphy proximal to Havre has yet to be reconstructed, which can reveal eruption history and...
Marine tephra layers are assigned to explosive volcanism that distributes volcanic material through submarine density currents, pyroclastic flows that travel over the sea, and/or as fall- out, but transitions or combinations of these emplacement processes are still under debate. In April 2022, the RV Investigator voyage IN2022-V02 surveyed submarine and island volca- noes and their adjacent...
The King’s Trough Complex (KTC), located around 700 km northeast of the Azores, is a remarkable canyon-like structure in the eastern North Atlantic Ocean. It consists of several deep basins: The huge King’s Trough in the west is flanked by elongated seamount-like structures, while the smaller Peake and Freen Deeps adjoining at its eastern opening are separated by the steep and narrow Palmer...
Recent studies suggest that mantle plumes are multifaceted structures, which transfer material and heat from the base of the lowermost mantle to the surface. The surface expression of a deep-rooted mantle upwelling is generally preserved as a crudely linear age-progressive hotspot track on the seafloor. The Tristan-Gough hotspot track (South Atlantic) is one of the most complex hotspot tracks...
Most, if not all, recent magmatic systems’ conceptual models depict magma accumulations either as sills (thin lenses) or laccoliths (mushroom-shaped magma bodies), typically with smooth top and bottom surfaces. Although it is speculated that the topography of a magma body might be one of the governing factors for building pathways along which magma ascents toward the surface, how do magma...
Submarine volcanoes have the potential to impact human societies and infrastructure on a global scale, yet due to their inaccessibility, there is limited knowledge of their internal architecture and evolution across space and time. Recent studies have shown that high-resolution seismic reflection imaging is a versatile tool for investigating volcanic systems, providing unique insights into...
The Christiana-Santorini-Kolumbo (CSK) volcanic field has hosted more than 200 explosive eruptions in the past 360,000 years, including the 1650 eruption of Kolumbo Volcano. Previous studies have established a temporal link between regional tectonics and volcanism in the CSK volcanic field. However, clear structural links between individual fault zones and volcanism have not been made...
Submarine volcanic eruptions and landslides have the potential to trigger devastating tsunamis that have been responsible for more than 55,000 casualties in historic times. The genesis of volcanogenic tsunamis is often complex and may involve underwater explosions, earthquakes, caldera subsidence, pyroclastic density currents, flank failures or a combination of such triggers. Even for...
Rates of lithification of young pyroclastic deposits, measured through precise determinations of material, physical and mechanical properties, provide important context for assessing the stability of emergent and submarine volcanoes and predicting seismic and volcanic hazards on these structures. At Surtsey volcano, a basaltic oceanic island created by a 1963–1967 eruption within the...
Axial Seamount is a submarine volcano in the Northeast Pacific Ocean at the intersection of the Cobb hotspot and the Juan de Fuca Ridge. The last eruption in 2015 was recorded by 7 ocean bottom seismometers (OBSs) on the Ocean Observatories Initiative Regional Cabled Array. Levy et al. (2018) obtained 100 composite focal mechanisms from manual first motion picks and S/P amplitude ratios for...
The Azores Plateau extends at its maximum of about 700 km from east of Santa Maria to west of Corvo and Flores and is separated by the Mid-Atlantic Ridge into the larger eastern and smaller western part. The Terceira Rift east of the MAR represents the boundary between the Eurasian and Nubian plates. Multibeam and yet unpublished reflection seismic data revealed abundant submarine volcanoes in...
The margins of the northeast Atlantic Ocean between Iberia and Newfoundland are generally described as being typical (magma-starved) passive margins. It is all the more astonishing that numerous features of excess volcanism, apparently formed shortly after continental breakup, dot the respective ocean basins including the Bay of Biscay. Understanding the opening of the Bay of Biscay and the...
The Reykjanes Ridge is a slow-spreading segment of the Mid-Atlantic Ridge. The 900 km long axis is constructed by overlapping and ‘en echelon’ arranged axial volcanic ridges (AVRs). Considering their typical geometry – length of 10-30 km, width of 200-500 m, and height of up to 500 m above the surrounding seafloor – neighboring AVRs, on average, overlap with each other over a distance of 1/3...
Submarine volcanic activity, which accounts for approximately 80% of Earth's volcanism, remains challenging to monitor. Recent studies have successfully utilized impulsive seismic events with dominant frequencies around 22 Hz to track freshly erupted lava on the seafloor in various submarine volcanic systems such as Axial Seamount, East Pacific Rise mid-ocean ridge, and offshore Mayotte...
The Reykjanes Ridge is a section of the slow-spreading Mid-Atlantic Ridge interacting with the Iceland plume. The ridge consists of “en echelon” axial volcanic ridges (AVR) displaying a large range of geometry and tectonic vs. volcanic ratio. The absence of trends in those variations associated with either the distance from the plume center or the presence of V-shape ridges indicates that the...
