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Turbidity currents and their deposits can be investigated using several methods, i.e. direct monitoring, physical and numerical modelling, sediment cores and outcrops. The present study focuses on thin clayey sand turbidites found in Lake Hazar (Turkey) occurring in eleven clusters of closely spaced This article is protected by copyright. All rights reserved.

An 8000-year lacustrine sediment record from Lake Motosu (Fuji Five Lakes) records several eruptions, including potentially unreported events, of the active Mt. Fuji volcano, which receives approximately 47 million annual visitors. A high-fidelity age model is constructed from tephra ages and high-density radiocarbon dating of terrestrial macrofossil and bulk organic matter. Variability in lake reservoir age is constrained by modern lake water radiocarbon measurement and reverse calibration of tephra calendar ages. We present more accurate ages for known eruptions, detect a wider distribution of ejecta for several eruptions, including the most recent summit eruption, and potentially identify previously undetected flank eruptions. There are closely spaced scoria-fall layers that may be difficult to differentiate as separate events in land-based surveys. These results demonstrate the utility of lacustrine sediments as powerful tools for understanding characteristics of volcanic eruptions.

This paper reviews recent case studies completed on mass movements (and landslide dams) with probable (post-) seismic origin or susceptible to seismic failure in the Tien Shan, Central Asia. Geophysical investigations and seismological and microseismic surveys presented here were carried out on the Kainama earthflow in the Southern Kyrgyz Tien Shan, on loess landslides in Tajikistan as well as on unstable slopes and a landslide dam in the Central Kyrgyz Tien Shan. The latter investigations were completed in summer 2011 using electrical tomography combined with seismic refraction and microseismic measurements as well as earthquake recordings. For all sites complex 3D models were built (with the GOCAD software). For some sites 2D numerical modelling of seismic slope stability allowed us to make accurate assessment of their susceptibility to seismic failure. Modelling of the seismic amplification potential of various slopes confirmed the results obtained from the seismological surveys: strongest amplifications generally affect the upper parts of the slope close to the crest of the mountains-not only due to topographic effects but also due to the presence of weaker rocks or thicker soft deposits in these areas. The results of the dynamic modelling further show that a combination of seismic and hydrologic factors (pore pressure build-up during the seismic shaking and post-seismic rise of groundwater level) was necessary to trigger the failure.