Crustal structure and composition

Hydraulic fracturing is known to induce seismic events, which is a concern for large-scale stimulations, for example, for exploitation of shale gas or geothermal energy. In our study on meter-scale hydraulic fracturing for stress measurements, we show that monitoring of seismicity along with refined seismicity location methods offers unique and ample insights into fracture growth processes. Fracture properties derived from seismicity reveal essential information about the stress state, thus helping to constrain other stress measurements.

The period between 1991 and 2005 was a time when many western geologists came to the Urals to get a closer look at this famous and extraordinarily rich region. The main reason was an openness policy of the USSR government, when foreigners were admitted to this area that was formerly almost closed. The co-operation of the western geologists with local specialists was very fruitful. The author aimed to describe the most interesting findings in Uralian geology after the learned guests left.

This paper presents the results of two experiments of revegetation techniques in context of water erosion and mountainous Mediterranean climate. We studied the interest of a wood chip amendment, applied on soil surface (mulch), and its interaction with plant development. The use of different plant species and the monitoring on three growing seasons (with climatic variations) allow us to specify the interest of wood chip mulch to improve revegetation especially in erosion and drought conditions.