Michael Stipp

The recrystallized grain size piezometer for quartz

D=1 0 3.56±0.27 * s 1.26 ±0.13 , with no change in slope at the regime 2–3 transition and no effect of temperature or a/b stability field. Another experimental piezometer relation for regime 1 of Hirth and Tullis [1992] differs in slope, suggesting that different recrystallization mechanisms require different piezometer calibrations. INDEX TERMS: 3902 Mineral Physics: Creep and deformation; 5120 Physical Properties of Rocks: Plasticity, diffusion, and creep; 8030 Structural Geology: Microstructures; 8159 Tectonophysics: Rheology—crust and lithosphere; 8164 Tectonophysics: Stresses—crust and lithosphere. Citation: Stipp, M., and J. Tullis, The recrystallized grain size piezometer for quartz, Geophys. Res. Lett., 30(21), 2088, doi:10.1029/2003GL018444, 2003.

Submarine mass movements and their consequences : 6th International Symposium

We present a short review of the state-of-the-art numerical tools that have been used for modeling landslide-generated waves. A comparative study is conducted on the physical properties of earthquake- and landslide-generated waves suggesting that both dispersion and nonlinearity effects may be neglected for the former waves whereas they may be considered for the latter ones. We introduce landslide tsunami models and group them into three classes: (1) models treating the moving mass as a fluid, (2) models estimating the initial water surface, and (3) models fed by the transient seafloor deformation. Selection of a particular model from the list of models introduced here depends on: (1) the dimensions of the source, (2) the available computing capacities, (3) availability of fine bathymetric grid, and (4) the purposes of the modeling.

Fahrtbericht / Cruise Report SO244/1 - GeoSEA: Geodetic Earthquake Observatory on the Seafloor, Antofagasta (Chile) - Antofagasta (Chile), 30.10.2015 - 24.11.2015

The majority of M>8.5 active plate boundary earthquakes has hypocenters located beneath the noceans in subduction zones. Post-hoc analysis shows that most of the surface deformation nrelated to co-seismic stress release takes place on the seafloor, in many cases unleashing major ntsunamis. The structure and morphology of the seafloor and shallow subbottom thus stores ncrucial information on sub-seafloor processes, such as permanent deformation by seismic slip or naseismic creep within the overriding plate and earthquake and tsunami generation. n nWe have mapped the seafloor seaward of the Northern Chilean coast between about 19°S and n22°S down to the Northern Chile deep sea trench, using the ship-based Multibeam Echosounder nEM122, Parasound, and AUV (autonomous underwater vehicle) – in selected subareas - at nsufficient resolution to identify active tectonic fault structures and submarine mass wasting nstructures, to quantitatively assess young and active deformation of the overriding plate in the narea, and quantify the extent of recent catastrophic downslope mass movements of sediment. nFurthermore, the investigations serve as a site survey for the deployment of the GeoSEA nseafloor geodetic array, to be installed immediately after completion of this cruise. n nThe investigations were made timely by the 1st April 2014 Pisagua M=8.2 earthquake, that nruptured the plate interface in the northern part of the area of investigation. The central and nsouthern parts are located in the last remaining locked seimotectonic segment along the Chilean nactive margin. In addition to providing the first data base for geomorphological and tectonic ninterpretation of geo-processes at the seafloor, the bathymetric mapping done during SO244 nLeg 1 will provide an important data reference for possible post-earthquake surveys once this nseismotectonic segment will have broken in the future.