Understanding the long-term earthquake recurrence pattern at subduction zones requires continuous paleoseismic records with excellent temporal and spatial resolution and stable threshold conditions. South central Chilean lakes are typically characterized by laminated sediments providing a quasi-annual resolution. Our sedimentary data show that lacustrine turbidite sequences accurately reflect the historical record of large interplate earthquakes (among others the 2010 and 1960 events). Furthermore, we found that a turbidite's spatial extent and thickness are a function of the local seismic intensity and can be used for reconstructing paleo-intensities. Consequently, our multilake turbidite record aids in pinpointing magnitudes, rupture locations, and extent of past subduction earthquakes in south central Chile. Comparison of the lacustrine turbidite records with historical reports, a paleotsunami/subsidence record, and a marine megaturbidite record demonstrates that the Valdivia Segment is characterized by a variable rupture mode over the last 900 years including (i) full ruptures (M w~9 .5: 1960, 1575, 1319 ± 9, 1127 ± 44), (ii) ruptures covering half of the Valdivia Segment (M w~9 : 1837), and (iii) partial ruptures of much smaller coseismic slip and extent (M w~7 .5-8: 1737, 1466 ± 4). Also, distant or smaller local earthquakes can leave a specific sedimentary imprint which may resolve subtle differences in seismic intensity values. For instance, the 2010 event at the Maule Segment produced higher seismic intensities toward southeastern localities compared to previous megathrust ruptures of similar size and extent near Concepciόn.

The Main Ethiopian Rift (MER, ~7-9 °N) is the type example of a magma-assisted continental rift. The rift axis is populated with regularly spaced silicic caldera complexes and central stratovolcanoes, interspersed with large fields of small mafic scoria cones. The recent (latest Pleistocene to Holocene) history of volcanism in the MER is poorly known, and no eruptions have occurred in the living memory of the local population. Assessment of contemporary

Soon after the onset of an eruption, model forecasts of ash dispersal are used to mitigate the hazards to aircraft, infrastructure, and communities downwind. However, it is a significant challenge to constrain the model inputs during an evolving eruption. Here we demonstrate that volcanic lightning may be used in tandem with satellite detection to recognize and quantify changes in eruption style and intensity. Using the eruption of Calbuco volcano in southern Chile on 22 and 23 April 2015, we investigate rates of umbrella cloud expansion from satellite observations, occurrence of lightning, and mapped characteristics of the fall deposits. Our remote sensing analysis gives a total erupted volume that is within uncertainty of the mapped volume (0.56 ± 0.28 km3 bulk). Observations and volcanic plume modeling further suggest that electrical activity was enhanced both by ice formation in the ash clouds >10 km above sea level and development of a low‐level charge layer from ground‐hugging currents.

Seismically‐induced event deposits embedded in the sedimentary infill of lacustrine basins are highly useful for palaeoseismic reconstructions. Recent, well‐documented, great megathrust earthquakes provide an ideal opportunity to calibrate seismically‐induced event deposits for lakes with different characteristics and located in different settings. This study used 107 short sediment cores to investigate the sedimentary impact of the 1960 Mw 9·5 Valdivia and the 2010 Mw 8·8 Maule earthquakes in 17 lakes in South‐Central Chile (i.e. lakes Negra, Lo Encañado, Aculeo, Vichuquén, Laja, Villarrica, Calafquén, Pullinque, Pellaifa, Panguipulli, Neltume, Riñihue, Ranco, Maihue, Puyehue, Rupanco and Llanquihue). A combination of image analysis, magnetic susceptibility and grain‐size analysis allows identification of five types of seismically‐induced event deposits: (i) mass‐transport deposits; (ii) in situ deformations; (iii) lacustrine turbidites with a composition similar to the hemipelagic background sediments (lacustrine turbidites type 1); (iv) lacustrine turbidites with a composition different from the background sediments (lacustrine turbidites type 2) and (v) megaturbidites. These seismically‐induced event deposits were compared to local seismic intensities of the causative earthquakes, eyewitness reports, post‐earthquake observations, and vegetation and geomorphology of the catchment and the lake. Megaturbidites occur where lake seiches took place. Lacustrine turbidites type 2 can be the result of: (i) local near‐shore mass wasting; (ii) delta collapse; (iii) onshore landslides; (iv) debris flows or mudflows; or (v) fluvial reworking of landslide debris. On the contrary, lacustrine turbidites type 1 are the result of shallow mass wasting on sublacustrine slopes covered by hemipelagic sediments. Due to their more constrained origin, lacustrine turbidites type 1 are the most reliable type of seismically‐induced event deposits in quantitative palaeoseismology, because they are almost exclusively triggered by earthquake shaking. Moreover, they most sensitively record varying seismic shaking intensities. The number of lacustrine turbidites type 1 linearly increases with increasing seismic intensity, starting with no lacustrine turbidites type 1 at intensities between V½ and VI and reaching 100% when intensities are higher than VII½. Combining different types of seismically‐induced event deposits allows the reconstruction of the complete impact of an earthquake.