Active Tectonics in the vicinity of the Alps

By -

Alpenseminar by Benjamin Schmitz

On the 27th of April we had a presentation on the active tectonics across the Alps by Benjamin Schmitz. To begin, we considered the tectonic setting across the Eastern Mediterranean by looking at the most recent Paleogeographic reconstruction of the Alpine orogeny.


Recent Paleogeographic setting of the Alpine orogeny, after Handy et al., 2015


The effect of the orogenesis linked to the indentation of the Adriatic Plate (brown on the above figure) into the European Plate (blue on the above figure) resulted in the formation of several faults and collisional zones. We may now consider: What tectonic effect remains?

To better elaborate on this question, we may now consider the GPS velocities across Europe, Asia and North Africa, which is further associated to Nubia-Eurasia-Convergence:




GPS-measured relative plate motions between the African and European/Eurasian Plates, after Facenna et al., 2014


Importantly, this only shows recent movements and does not necessarily highlight plate movement associated to geological time. However, interestingly, these motions highlight a lack of movement within the Alpine region. We may now ask: Where did the movement go? 

Now, to better elaborate on this question, we may consider the stress measurements as collated by the World Stress Map:


Stress field measurements across the Mediterranean region, after the World Stress Map, 2016


The stress data therefore suggests that recent tectonic movement in the Alps may not be related to active plate tectonic effects linked to active plate boundaries, e.g. subduction or mid oceanic ridges. We may now consider the effect of topographic stress forces, and the associated gravitational effect:


Estimated 90% of overall uplift associated to deglaciation in the Alps, modified after Mey et al., 2016


And, finally, we can look at the recent seismicity (earthquake locations) across the Alps:


Seismicity across the Alps, after SPP-4D Programme


And, now we may summarise the active tectonics across the Alps:

1. No significant deformation associated with the Alpine Orogeny
2. Greater effect associated to Topographic forces, i.e. deglaciation

Comments

Post a Comment

Popular posts from this blog

Paleogeography of the Alps

By Unknown -
Image
Alpenseminar by Taufeeq Dhansay The formation of the Alpine Mountains can be broadly defined by the convergent movement of several continental plates and the associated opening and closing of oceanic basins. The science of Paleogeography aims to travel back in deep time and figure out how these different plates would have moved, and ultimately collided to form these magnificent mountains.  The protagonists Firstly, we should identify the main players (i.e. plates) in this story. This includes the larger African/Nubian and European plates, and the smaller Adriatic/Apulian and Iberian Plates. Below is a figure of the present-day alps and how its underlying tectonic units fit together: Broad overview of the major plates associated with the Alpine Orogeny, after  Handy et al., 2010 Importantly, zones between these plates (i.e. demarcated by darker colours on the above map) represent regions that, in particular, experienced varying levels of tectonism and/metamorp
Read more

Historical and Catastrophic Landslides

By Unknown -
Image
Alpenseminar and Blog post by Thomas Biehl On the 14th of May we had a presentation about really impressive and destructive landslides in the Alps. These landslides are generally related to large earthquakes and there are few examples that we may consider here: 1. Dobratsch - Carinthia In 1348 a destructive earthquake occurred near the town of Villach on the Austrian/Italian border. This earthquake resulted in several landslides along the 2166 m high Dobratsch massif, which lies atop the Periadriatic Lineament. Overview of the Dobratsch landslides, after  Lenhardt, 2007   The largest of these landslides was known as the "Rote Wand". This caused the destruction of a dam and the flooding of the whole Gail River Valley. Overview of the regional structure of the Dobratsch Mountains, after Stefan et al., 2004 2. Köfelsberg - Tirol Rapid Alpine deglaciation during the Holocene, approximately 9000 BC, resulted a massive landslide near th
Read more