Conveners
Subsurface & Surface Processes: SSP one
- Thor Hansteen (GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, DE)
Subsurface & Surface Processes: SSP two
- Jost v.d. Lieth (University of Hamburg)
- Corrado Cimarelli (University of Munich)
Subsurface & Surface Processes: SSP three
- Jörg Hasenclever (Universität Hamburg)
- Boris J.P. Kaus (Johannes Gutenberg-Universität Mainz)
The distributed volcanic fields of the West German Eifel region had their last eruptions less than 13,000 years ago. Recently, so-called deep low frequency (DLF) earthquakes were discovered under one of the Quaternary volcanic fields, which gives clear evidence of ongoing magmatic activity in the lower crust. Complementary gas geochemical, petrological and volcanological investigations support...
Seismic tomography is the state-of-the-art technique for imaging the Earth. When applied to magmatic systems, phase-dependent imaging (e.g. travel-time tomography or noise interferometry) has shown the potential to broadly resolve magmatic anomalies. Here, I show recent advances in tomographic imaging of collisional continental structures at the upper mantle scale in SE Asia, with their...
Oldoinyo Lengai volcano, located in the Natron Basin (Tanzania), is the only active natrocarbonatite volcano world-wide. As such, it presents an important endmember magmatic system, which occurs in a young rift segment (~3 Ma) of the East African Rift System. At this volcano, effusive episodes of long-duration are interrupted by short-duration explosive eruptions. At the end of February 2019,...
Volcanic activity is one of the main natural hazards and may cause damage to life and infrastructure. Therefore, investigation and monitoring of volcanic activity is crucial in mitigating volcanic risk. Since transport processes in the conduit have a major impact on eruption dynamics, understanding conduit processes is of great interest. Unfortunately, direct measurements of these processes...
The transport of magma and magmatic fluids is often the key process having the main control on the occurrence, duration and intensity of various volcanic crises. Volcano gravimetry allows for an unequivocal inference of the location and associated mass of accumulated or removed magmatic fluids at volcanoes. This task is best accomplished through collecting gravity time series at multiple...
Low-δ18O rhyolites have been a petrological conundrum as they reflect silicic magma generation in the shallow and relatively cold upper crust (<400 °C), a region thought to be unfavorable for the production of large melt volumes. Their genesis is therefore crucial in understanding what keeps large silicic magma reservoirs in the upper crust alive over timescales of millions of...
Plinian eruptions inject gases, aerosols, and fine ashes into the stratosphere, potentially influencing climate. The amounts of volatiles emitted from such eruptions are typically estimated using the difference between contents in silicate melt inclusions formed at depth and those in the groundmass of glassy tephras (the so-called petrologic method). We have compared chlorine emission data...
The 5$^{\rm th}$ international Vulcano Summer School was a great opportunity to collect spectral data in an environment characterized by a large variety of volcanic and hydrothermal altered products. Our main goal was to investigate the in situ spectral response of a vast assortment of volcanic and hydrothermal deposits and compare these results with data collected in laboratory experiments....
Rising magmas are subjected to volatile exsolution due to decompression, which induces bubble nucleation, growth and coalescence. Although degassing strongly depends on melt and volatile composition, similar magmas can feed eruptions with different degree of explosivity, which in turn appears to be well-correlated with decompression rate. A better knowledge of volatile degassing mechanisms...
Mid Ocean Ridge Basalts (MORBs) represent the most abundant magmatic composition on Earth. Yet, their rheology had not been extensively experimentally investigated so far, hindering our ability to attain quantitative models of their emplacement processes. We thus obtained a series of detailed measurements on the rheology of a mid-ocean ridge basalt representing the average composition of MORB...
Submarine hydrothermal systems sustain unique ecosystems, affect global-scale biogeochemical ocean cycles, and mobilize metals from the oceanic crust to form volcanogenic massive sulfide deposits. Understanding and quantifying the involved processes requires linking seafloor observations to physico-chemical processes at inaccessible depth; here numerical models of hydrothermal circulation...
For the past decades, several numerical studies have successfully reproduced the concentric uplift pattern observed above the Altiplano-Puna Magma Body (APMB) in the central Andes. However, the temperature- and strain rate-dependent viscoelastoplastic rheology of rocks, the buoyancy of magma, the effects of modelling in 3D as well as the shape of the magma body have often been simplified or...
The Strombolian eruption style, named after Stromboli volcano (Italy), can be attributed to large gas slugs that coalesce from exsolved gas bubbles during their ascent inside the volcanic conduit. Moreover, field observations at the vent reveal that eruptions consist of pulses on the order of a few seconds. One possible explanation for this behaviour is a constricted conduit through which the...
In theory, pockets of fluid in brittle media can be transported large distances, provided that both the fluid volume is large enough, such that fluid pressures can fracture the rock, and that stress gradients exist causing asymmetric growth of the fracture's front. Currently, industrial injections are deemed safe based on empirical observations of volumes, rates and pressures from...
Volcanoes may erupt dominantly at their summit or on their flanks, depending on a number of reasons including edifice shape, magma composition, tectonic setting. At calderas, which lack a summit to focus ascending magma, eruptive vents are often scattered within or around the caldera rim, distributed in patterns that may have shifted over the history of the volcanic complex. The scattered...
