Laacher See Volcano
About 13,000 years ago, Laacher See produced one of the largest volcanic eruptions in Central Europe during the Late Pleistocene. Traditionally, its magma was thought to have evolved in a large, shallow reservoir beneath the volcano for tens of thousands of years. Click here to access the full publication.
In this study, my co-authors and I tested a different idea: that most of the magma evolved much deeper in the crust. High-pressure experiments show that magmas crystallizing at depths of roughly 13–28 km can develop compositions very similar to those erupted at Laacher See.
Our results suggest that magma differentiation took place mainly below about 15 km depth, before evolved melts accumulated in the middle crust at around 12–14 km (Fig. 1). Only shortly before the eruption did part of this magma move upward and assemble a shallow reservoir at about 5 km depth, potentially within months to years.
This supports a broader view of volcanic systems in which magma is stored and modified across many levels of the crust, while shallow magma chambers may be short-lived features that form rapidly before an eruption.
Fig. 1. A model for the evolution of the magma system beneath the East Eifel.
(a) Magma accumulated and evolved mainly deep in the crust over tens of thousands of years.
(b) Shortly before the Laacher See eruption about 13,000 years ago, a new magma injection destabilized this deeper system and drove magma rapidly toward the surface, temporarily forming a shallow reservoir.
(c) Today, COâ‚‚ emissions and earthquakes indicate that magmatic fluids continue to move beneath the region.
Rieden Volcano
Around 400,000 years ago, the Rieden Volcanic Complex was the major volcanic centre of the East Eifel. It was active repeatedly over tens of thousands of years, producing around 15 eruptions, including several large explosive events with high eruption columns and pyroclastic flows.
In this study, we identified ash from four of these eruptions in sediment cores from the nearby Dottinger Maar, about 15 km away. The deposits show that Rieden erupted under various environmental conditions, including during a cold glacial period and during transitions into warmer climates (Fig. 2). One particularly large eruption left an ash layer about 1.3 metres thick at Dottinger Maar. Click here to access the full publication.
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Fig. 2. The sediment record from Dottinger Maar is compared with global climate records to reconstruct environmental change between about 450,000 and 390,000 years ago. Changes in organic matter and pollen document the transition from the cold Elsterian glacial period to the warmer Holsteinian interglacial. The red lines mark ash layers from eruptions of the Rieden Volcanic Complex, showing that volcanic activity occurred across both cold and warm climate conditions.
