A swarm of devastating caldera-forming eruptions (>VEI 6) blanketed the Permo-Carboniferous of central Europe with voluminous pyroclastic deposits within a long-lasting period of 50 Myrs. Although of different tectonic setting, the pyroclastic record of this ignimbrite flare-up is similar to the Cenozoic deposits in the western USA, ranging from crystal-poor rhyolitic Snake River-type and compositionally zoned tuffs to crystal-rich monotonous intermediates and rhyolites.

Combined textural and chemical analysis data on whole rock, juvenile fragments (fiamme, glass shards), and mineral phases were acquired to unravel the origin and lithospheric evolution of the magma reservoirs. Two different geochemical suites can be distinguished: (I) a diopside- and (II) a corundum-normative. Examples of the diopside-normative suite are the caldera systems of Wurzen and the Wendland, as well as the vitrophyric Planitz Ignimbrite. Although all pyroclastic deposits show corundum-normative compositions; solely, the magma system of the Flechtingen Ignimbrite crystallizes almandine-garnet in a deep-seated magma chamber. In general, thermobarometric estimations suggest an interplay of hydrous near-solidus granitic systems penetrated by anhydrous SiO₂-rich superheated magmas. These systems can be tracked down to depths of 25 to 40 km (7-12 kbars) and provide insights into the post-Variscan rift-related magmatic activity.

A sudden eruption occurred in December 2022 at Lascar, one of the most popular volcanoes for tourists in Chile. Following the eruption, lava emplacement was observed in summit crater of Lascar. Due to volcanic activity and inaccessibility, we acquired a series of Pleiades tri-stereo satellite images covering this unrest episode. We generated high resolution point clouds and orthomosaics from the satellite images using photogrammetric approaches. We analyze point clouds to quantify morphological and structural details and changes. We found that the crater floor initially uplifted due to lava extrusion and rockfall deposition, and subsequently the crater floor subsided and formed a funnel in the center. To understand the mechanical factors controlling the uplift and subsidence, we designed a novel set of analogue experiments using sand-plaster mixtures to simulate lava extrusion and subsidence from same conduit. We account for topographic effects by running experiments on flat plate and 3D printed mould of the Lascar crater, respectively. We use 2D digital image correlation method to record and visualize displacements during extrusion and subsidence. The results show that extrusion and subsidence occurs along distinct shear faults, which are constrained by conduit diameter and represented as concentric fractures at surface. We develop a conceptual model that lava extrusion is affected by withdrawal from the conduit, forming a funnel-shaped surface depression associated with inward-dipping radial erosion gullies. Thus, combining satellite observations and analogue models help to identify the position and dimension of the underlying conduit, which is essential for understanding future activity of Lascar volcano.

Two diatreme structures in the Lusatian Mountains (CZ) can be assigned to so-called pre-rift period of volcanism within the Bohemian Massif. This is confirmed by Ar-Ar age determinations on intrusive ultramafic melilithic rocks in the diatremes of Dolní Falknov (≤ 68.34 ± 0.33 Ma) and Stožec (68.80 ± 0.85 Ma). Detailed geological mapping of both volcanic structures enabled to clearly demonstrate typical diatreme breccia only in the Dolní Falknov diatreme. In contrast, mapping of the Stožec volcanic structure 5 km to the northeast only revealed an intense red-brown coloured diamictite deposit. This diamictite also occurs in the top of the Dolní Falknov diatreme fill as separated clods and is interpreted as a collapse breccia. The diamictite as well as the diatreme breccia contain numerous rounded pebbles of different lithologies with diameters of up to 0.5 m. Some of these pebbles probably come from Permian rocks (Rotliegend) and indicate a multi-phase redeposition history. These could be erosion products from the Lausitz Block, which is located 2.5 and 5 km north of the two diatreme structures. The Permian sediments eroded here were later rounded off before being redeposited as terrestrial (red) sediments in the uppermost Upper Cretaceous (Campanian–Maastrichtian). These deposits have only been preserved due to their sheltered position within the pre-rift diatreme structures.

Recent discoveries and studies of maars in the NE Bavaria-Czech Republic border region have significantly expanded our knowledge of Cenozoic volcanism in the western Bohemian Massif. Using geomorphological and geophysical investigations, two new circular geological structures with partly striking geophysical anomalies were discovered: the Bärnau Maar and the Rohrloh Maar. They were explored with two scientific drillings by the Geological Survey at the Bavarian Environment Agency. Both dry maars form shallow depressions from a few hundred to approximately 1000 m in diameter. In the Bärnau Maar, a 150 m thick sedimentary sequence consisting primarily of laminated, organic-rich clayey to silty sediments with numerous diatomite laminae of a lacustrine depositional environment was drilled, with frequent sand beds and soft-sediment deformation structures documenting repeated turbidity flows and slumps. The upper sedimentary sequence comprises soft-sediment deformed lacustrine sediments overlain by gravelly and sandy deposits. The 70 m thick sediment sequence drilled in the Rohrloh Maar similarly consists predominantly of fine-grained lacustrine sediments with intercalated sandy turbidite beds. Both sediment sequences are composed predominantly of quartz-, mica-, and kaolinite-rich sediments, representing the erosion products of neighbouring crystalline rocks; however, elevated smectite contents near both core bases suggest the contribution of juvenile material. The palynological data from the Bärnau Maar and Rohrloh Maar sediments advocate a Lower to Middle Miocene age and Lower Miocene age, respectively. During this time, the climate was predominantly subtropical to temperate, and swamp forests surrounded the maars, whereas mesophytic vegetation was present in the broader region.

Regions with complex topography display a variable degree of deformation during seismic and volcanic events. In the Reykjanes Peninsula rift, both extension and strike-slip motion result from its highly oblique angle with respect to the plate opening, leading to NE- and N-striking structures, including eruptive fissure swarms, tensile fractures, normal faults and strike-slip faults. Structural domains have been explained by factors like tectonomagmatic cycles or proximity to rift axes. However, pre-existing topographic gradients were not previously considered relevant for the resulting fracture network of the area, as suggested by studies at other sites.

Following a period of uplift in the Svartsengi volcanic system, a 2-meter-deep graben formed in November 2023 due to a ~15-km long dike intrusion. In this work, we use high-resolution photogrammetric data from before and after this event to explore how Mount Thorbjorn, situated on the western part of the graben, responded to this deformation event. A Digital Elevation Model (DEM) difference map suggests tilting of the mountain towards the east and reactivation of pre-existing faults. Comparison of orthophotos before and after the event revealed new surface fractures, many corresponding to reactivated buried discontinuities, mainly expressed as normal motion and with fissures showing opening. Statistical analyses were used to test the topographic controls on the resulting faulting pattern, and sandbox analogue experiments helped better understand the process. Preliminary results suggest that the distribution of the fractures is influenced by topography, with denser patterns observed in higher elevation areas, and changes in their strike due to surface adjustments.

Hekla is one of the most active volcanoes in Iceland, with recent eruptions in 1970, 1980-81, 1991, and 2000. The last three eruptions occurred in the early months of the year when the volcano was heavily snow-covered. As a result, tephra and effusive deposits have covered large amounts of snow and ice causing an insulation effect. Using photogrammetric processing and GIS analysis of historical aerial photographs (1945-1982), recent Pléiades satellite tri-stereo images (2022 and 2023), and UAV data acquired during the 2022 and 2023 fieldwork, we found evidence of intense cryospheric processes such as rock glacier emplacement and multiple thermokarst formations. Our results show that the NW flank of Hekla is covered by 6 distinct rock glacier lobes that were recently (after 1982) emplaced atop previously formed rock glaciers identified in 1945-1982 datasets. The total area of the recent rock glaciers is about 2 km². The longest lobe reaches 1.4 km in length and has a 50 m front thickness. The lobe has advanced by 13 m over 1 year (2022-2023). The newly emerged thermokarst sinkholes have been observed in the field in the summit area and on the NE flank. These aspects of Hekla's evolution may play a significant role in the magnitude of hazards in case of future unrest. The emplacement of lava along rock glaciers and permanent snow raises the risk of impending lahars. Volcanic heat can expedite permafrost degradation and the advancement of rock glaciers, culminating in significant landslides.