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Results from geophysical explorations of three deep valleys, selected from different tectonic regimes in the Eastern Alps (Ö tz-, Oichten-, and Drau Valley), are presented and discussed. Ongoing tectonic deformation may use tectonic structures related to these valleys. However, seismic activity is low there. During the Würm ice age, the thickness of the ice cover ranged between 300 and 1,500 m above present ground elevation. The geophysical investigations comprised reflection seismology, gravityand resistivity surveys. The maximum depth down to the erosional base of the valleys varies from *340 to 700 m. Distinct layer packages of the valley-infill at depths greater than 250 m were termed ''old valley-fill''. Geophysical parameters and a comparison with the reflection seismic image of an intermediate layer at the recent Pasterze glacier suggest that the top of the ''old valley-fill'' represents the glacier bed during the decay of the Würm glaciation. Deep erosion is not related to high basal shear stress. The confluence of tributary glaciers is apparently not a significant factor for deep erosion in our examples of deep alpine valleys. We conclude that deep erosion may be related to high water pressure at the glacier bed, supported by specific processes of tectonic weakening.

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<p>The MacroSeismic Sensor network (MSS network) is a dense layout of 46 custom-built seismic low-cost sensors in populated area in the southern part of the Vienna Basin, Austria. The recorded ground-motion is sent to a central server using the Internet, processed on the server and then visualized in a web application in near real-time. The MSS network has been started 2014 by a funding program dedicated to the participation of young people and “Citizen Science” (Sparkling Science - a program of Federal Ministry of Education, Science and Research Austria) and has been further developed and kept in operation by private and public funding, participation of public schools as well as voluntary contribution of individuals.</p><p>The MSS uses 4.5 Hz geophones, 16bit analog-to-digital conversion (ADC) at a sampling rate of 100 samples per second and the Seedlink protocol for data transmission. A Raspberry Pi single board computer is used for controlling a custom-built ADC circuit board, data transmission and communication. Time synchronization is done using the Network Time Protocol.</p><p>For the visualization, the peak-ground-velocity is computed using 2 horizontal components at a sampling rate of 1 sample per second. An amplitude threshold algorithm using the Delaunay triangulation of the MSS network is used for the detection of seismic events and an amplitude-based localization method is used to compute the epicenter of the events.</p><p>The peak-ground-velocity and the detected events are presented on a map display by the web application with a focus of an intuitive presentation of the current state and the short-term history of the ground-motion within the area of the MSS network.</p><p>The output of the MSS network is used by public and private institutions. The the regional hazard warning center of Lower Austria (Landeswarnzentrale Niederösterreich) has integrated the MSS network visualization into their infrastructure to inform and warn the general public in case of a strong ground-motion in the area. A local quarry operator uses the data of the MSS network for a transparent monitoring and documentation of their blasting activity.</p>