Research on the February 18, 1996 earthquake in the caves of Saint-Paul-de-Fenouillet area, (eastern Pyrenees, France)

Eight caves have been investigated near Saint-Paul-de-Fenouillet after the earthquake of 5.2 magnitude of February 1996 which occurred in the eastern Pyrenees (France) and caused moderate damage at the ground surface. The earthquake has been associated with the movement of an E-W fault. The caves had not been visited since the earthquake. Some damage, mainly collapses of soda straws and small rocks, could be attributed to this earthquake. The most interesting cave in the epicentral area is the Paradet cave which is situated on a recently activated fault plane. In this cave, soda straw falls could be attributed to the earthquake, but other more ancient damage was also observed. Analysis of the azimuth of fallen speleothems, which are natural pendulums, may indicate the directions, and an estimation of their mechanical properties gives the threshold of the seismic ground motion amplitude responsible for their collapse, thus supplying information to calibrate damage due to past earthquakes. A statistical study indicates that the main direction of the collapsed soda straws is E-W. Numerical simulations confirm that soda straws are relatively strong objects that may break under certain conditions during earthquakes

The 14 August 1708 Manosque, France earthquake: new constraintson the damage area from in-depth historical studies

In this paper, we re-evaluate the damage area of the 14 August 1708 Manosque earthquake, Southeast France. It is the strongest event (Io = VIII MSK) of a seismic sequence that lasted from March to October 1708. We show that the spatial repartition of the damage that can be proposed based on the existing sources, is clearly biased by the abundant narrative information concerning Manosque. This sparseness in the information can be attributed to differences in communication routes or strategies between the different localities, and affects the global perception of the event, especially in the rural area. To tackle this bias, we propose to inventory the building repairs reported in non-narrative sources in order to capture the effects of the Manosque earthquake in the surrounding region. The debates and accounts (between mid-1708 and 1710) show that moderate to heavy repairs consistently affect localities in the epicentral area, covering a region of at least 12 km radius around Manosque. These building repairs, indirectly attesting to earthquake damage, provide valuable and complementary information, which resulted in a better knowledge of this event. In particular, we propose new intensity estimates (I >VI) at six localities

The French macroseismic database SISFRANCE: objectives, resultsand perspectives

To comply with nuclear safety requirements, an in-depth research program for the revision of existing catalogues was initiated back in 1974. The priority of the partners involved in the SISFRANCE project was to establish the most exhaustive documentary databank in order to construct an intensity macroseismic database, concerning both epicentral and punctual observations. The architecture of the SISFRANCE database is presented. The strength of this parametric database is the attribution of reliability coefficients at all levels of interpretations going from the documentary sources to the final intensity estimate. To ensure homogeneity of the database, a general guideline was defined. The resulting macroseismic relational database SISFRANCE contains 65000 intensity observations attesting to the existence of 5283 earthquakes (575 with Io = VI) that have been felt on the French metropolitan territory over the past one thousand years. Thanks to the homogeneous methodology and to the continuous collaboration between BRGM, EDF and IRSN for the past 30 years, SISFRANCE is today a reference database and a key tool for seismic hazard assessment

The 14 August 1708 Manosque, France earthquake: New constraints on the damage area from in-depth historical studies

In this paper, we re-evaluate the damage area of the 14 August 1708 Manosque earthquake, Southeast France. It is the strongest event (I 0 = VIII MSK) of a seismic sequence that lasted from March to October 1708. We show that the spatial repartition of the damage that can be proposed based on the existing sources, is clearly biased by the abundant narrative information concerning Manosque. This sparseness in the information can be attributed to differences in communication routes or strategies between the different localities, and affects the global perception of the event, especially in the rural area. To tackle this bias, we propose to inventory the building repairs reported in non-narrative sources in order to capture the effects of the Manosque earthquake in the surrounding region. The debates and accounts (between mid-1708 and 1710) show that moderate to heavy repairs consistently affect localities in the epicentral area, covering a region of at least 12 km radius around Manosque. These building repairs, indirectly attesting to earthquake damage, provide valuable and complementary information, which resulted in a better knowledge of this event. In particular, we propose new intensity estimates (I > VI) at six localities

The 14 August 1708 Manosque, France earthquake: new constraintson the damage area from in-depth historical studies

In this paper, we re-evaluate the damage area of the 14 August 1708 Manosque earthquake, Southeast France. It is the strongest event (Io = VIII MSK) of a seismic sequence that lasted from March to October 1708. We show that the spatial repartition of the damage that can be proposed based on the existing sources, is clearly biased by the abundant narrative information concerning Manosque. This sparseness in the information can be attributed to differences in communication routes or strategies between the different localities, and affects the global perception of the event, especially in the rural area. To tackle this bias, we propose to inventory the building repairs reported in non-narrative sources in order to capture the effects of the Manosque earthquake in the surrounding region. The debates and accounts (between mid-1708 and 1710) show that moderate to heavy repairs consistently affect localities in the epicentral area, covering a region of at least 12 km radius around Manosque. These building repairs, indirectly attesting to earthquake damage, provide valuable and complementary information, which resulted in a better knowledge of this event. In particular, we propose new intensity estimates (I >VI) at six localities

The French macroseismic database SISFRANCE: objectives, resultsand perspectives

To comply with nuclear safety requirements, an in-depth research program for the revision of existing catalogues was initiated back in 1974. The priority of the partners involved in the SISFRANCE project was to establish the most exhaustive documentary databank in order to construct an intensity macroseismic database, concerning both epicentral and punctual observations. The architecture of the SISFRANCE database is presented. The strength of this parametric database is the attribution of reliability coefficients at all levels of interpretations going from the documentary sources to the final intensity estimate. To ensure homogeneity of the database, a general guideline was defined. The resulting macroseismic relational database SISFRANCE contains 65000 intensity observations attesting to the existence of 5283 earthquakes (575 with Io = VI) that have been felt on the French metropolitan territory over the past one thousand years. Thanks to the homogeneous methodology and to the continuous collaboration between BRGM, EDF and IRSN for the past 30 years, SISFRANCE is today a reference database and a key tool for seismic hazard assessment

Determination des mouvements sismiques de reference pour les sites nucleaires en France

SIGLEAvailable from CEN Saclay, Service de Documentation, 91191 - Gif-sur-Yvette Cedex (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc