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Earthquake Mechanisms of the Mediterranean Area (EMMA) version 3: an improved tool for characterizing the tectonic deformation styles in the Mediterranean
No full textGeophysical Research Abstracts,
Vol. 11, EGU2009-7974, 2009
EGU General Assembly 2009
© Author(s) 2009
Earthquake Mechanisms of the Mediterranean Area (EMMA) version 3:
an improved tool for characterizing the tectonic deformation styles in the
Mediterranean.
G. Vannucci (1), P. Imprescia (2), and P. Gasperini (3)
(1) INGV-Istituto Nazionale di Geofisica e Vulcanologia, Via Donato Creti, 12, I-40128, Bologna (Italy), [email protected],
(2) Dipartimento Scienze Geologiche, Università di Catania, Corso Italia, 57, I-95129 Catania (Italy), [email protected],
(3) Dipartimento di Fisica, Università di Bologna, Viale Berti-Pichat 8, I-40127 Bologna (Italy), [email protected]
EMMA (Earthquake Mechanisms of the Mediterranean Area) database contains available literature data with the
goal of making them more usable and available. EMMA is continuously improving by the addition of further
focal mechanisms found in literature. At the present time, EMMA pre-release 3 includes more than 12700 focal
solutions, about twice of previous official release 2.2 (Vannucci and Gasperini, 2004). They cover a time window
from 1905 to 2006. In the new release, many added solutions are in areas not much covered or completely
uncovered in the previous one (e.g. Bulgaria, Germany, Anatolia).
As in the previous versions (Vannucci and Gasperini, 2003 and 2004), we have uniformed the different formats
and notations of the data available from different sources and we have tried to solve misprints, inaccuracies and
inconsistencies that might make the data unusable for other investigations. By an automatic procedure based on
several criteria, we have chosen the “most representative” (best) solution when more than one is available for
the same earthquake. Thanks to this, we have obtained about 6000 best solutions. The end user can use the best
solution obtained with our procedure or he can change criteria.
The database allows to make selections and to export data files suitable to be handled by graphic software and
user generated scripts. In the new version, still MS-ACCESS based, we have added geographic information to
the display of the focal solution, as well as we have integrated the hypocentral and magnitude data found on the
original papers with those reported by regional and local catalogs and bulletins.
In order to make EMMA more accessible, a web version is currently in progress. Through an internet connection
it will be possible data selection and export, without installation and configuration problems found in the past.
EMMA was already used in the past and will be (hopefully) useful in the future to better characterize the tectonic
deformation styles (e.g. by moment tensors sum within given areas or over regular geographical grids) particularly
in areas of the European region where seismicity is moderate and only few CMT solutions are available.
At the moment, we try to compute strain map for Mediterranean area, using EMMA data. In order to represent
any recurrence in space, we identify small areas and apply to each one some spatial analyses. The work is still in
progress, but preliminary results are satisfactory and in accord to previous studies.PublishedWien5.2. TTC - Banche dati di sismologia strumentaleope
Earthquake Mechanisms of the Mediterranean Area (EMMA) version 3: an improved tool for characterizing the tectonic deformation styles in the Mediterranean
No full textGeophysical Research Abstracts,
Vol. 11, EGU2009-7974, 2009
EGU General Assembly 2009
© Author(s) 2009
Earthquake Mechanisms of the Mediterranean Area (EMMA) version 3:
an improved tool for characterizing the tectonic deformation styles in the
Mediterranean.
G. Vannucci (1), P. Imprescia (2), and P. Gasperini (3)
(1) INGV-Istituto Nazionale di Geofisica e Vulcanologia, Via Donato Creti, 12, I-40128, Bologna (Italy), [email protected],
(2) Dipartimento Scienze Geologiche, Università di Catania, Corso Italia, 57, I-95129 Catania (Italy), [email protected],
(3) Dipartimento di Fisica, Università di Bologna, Viale Berti-Pichat 8, I-40127 Bologna (Italy), [email protected]
EMMA (Earthquake Mechanisms of the Mediterranean Area) database contains available literature data with the
goal of making them more usable and available. EMMA is continuously improving by the addition of further
focal mechanisms found in literature. At the present time, EMMA pre-release 3 includes more than 12700 focal
solutions, about twice of previous official release 2.2 (Vannucci and Gasperini, 2004). They cover a time window
from 1905 to 2006. In the new release, many added solutions are in areas not much covered or completely
uncovered in the previous one (e.g. Bulgaria, Germany, Anatolia).
As in the previous versions (Vannucci and Gasperini, 2003 and 2004), we have uniformed the different formats
and notations of the data available from different sources and we have tried to solve misprints, inaccuracies and
inconsistencies that might make the data unusable for other investigations. By an automatic procedure based on
several criteria, we have chosen the “most representative” (best) solution when more than one is available for
the same earthquake. Thanks to this, we have obtained about 6000 best solutions. The end user can use the best
solution obtained with our procedure or he can change criteria.
The database allows to make selections and to export data files suitable to be handled by graphic software and
user generated scripts. In the new version, still MS-ACCESS based, we have added geographic information to
the display of the focal solution, as well as we have integrated the hypocentral and magnitude data found on the
original papers with those reported by regional and local catalogs and bulletins.
In order to make EMMA more accessible, a web version is currently in progress. Through an internet connection
it will be possible data selection and export, without installation and configuration problems found in the past.
EMMA was already used in the past and will be (hopefully) useful in the future to better characterize the tectonic
deformation styles (e.g. by moment tensors sum within given areas or over regular geographical grids) particularly
in areas of the European region where seismicity is moderate and only few CMT solutions are available.
At the moment, we try to compute strain map for Mediterranean area, using EMMA data. In order to represent
any recurrence in space, we identify small areas and apply to each one some spatial analyses. The work is still in
progress, but preliminary results are satisfactory and in accord to previous studies.PublishedWien5.2. TTC - Banche dati di sismologia strumentaleope
Earthquake Mechanisms of the Mediterranean Area (EMMA) Database 3.0: First-Motion Focal Mechanisms and Their Ability to Characterize the Tectonic Deformation Style
No full textWe present a new version (3.0) of the database of Earthquake Mechanisms of the Mediterranean Area (EMMA) of "checked" first-motion focal solutions. The database, developed on MS-ACCESS, uniforms the different formats and notations of the data available in the literature and try to solve misprints, inaccuracies and inconsistencies that make them almost useless for other users (e.g. tests the perpendicularity of nodal planes and/or P and T axes of all solutions and, when both axes and planes are given, even their mutual consistency). An automatic procedure, based on several criteria, permits to choose the most "representative" (best) solution when more than one is available for the same earthquake. The database allows to make selections on the earthquake data and to export data files suitable to be handled by graphic software and user written procedures. For the Mediterranean region the first-motion focal mechanisms available from the literature allows to extend back in time, and to a lower magnitude threshold the data coverage of Centroid Moment Tensor (CMT) focal solutions of available Catalogs (Harvard University, Istituto Nazionale di Geofisica e Vulcanologia, Eidgenossische Technische Hochschule, Instituto Andaluz de Geofisica, USGS). With respect to the previous available version (2.1) we improve (+20%) the number of the data (about 7700 focal solutions at present), we add geographic information to the display of the focal solution plot, we permits to display the best solution and the other ones discarded (i.e. non-best). To solve some bias and inconsistence of the collected original data we also add to each mechanism the hypocentral parameters and the magnitude taken from the International Seismological Centre (ISC) Catalog. We verify the ability of EMMA database to characterize the tectonic deformation style, computing the cumulative moment tensor in the Mediterranean area on a regular grid with different seismogenic thickness, using the EMMA and CMT data separately. Then we use the rotational angle that should be applied to a cumulative focal mechanism to make it coincide with another one to verify the main differences between these patterns and the ability of EMMA database to reproduce the CMT Catalogs. To verify the quality of EMMA database we take advantage from some recent analyses that evidenced a relation between the Gutenberg- Richter b-value and the tectonic style of seismic release (in particular extensional mechanisms would correspond to higher b-values than compressive ones). We correlate the tectonic style as deduced from the cumulative moment tensor, previously detected, with the b-value computed by the ISC Catalog. We verify a good correlation between b-value and tectonic style using focal mechanisms taken from EMMA database
The new release of the database of Earthquake Mechanisms of the Mediterranean Area (EMMA Version 2)
No full textThe analysis of fault plane solutions of earthquakes is carried out in most seismotectonic studies to characterize the tectonic deformation styles and to estimate strain and stress directions in the investigated areas. Nevertheless the data available in the literature, are reported with different formats and notations and, in most cases, only in papery form, so that they are not suitable to be handled by computer procedures and graphic packages. Sometimes the data are reported with typographical errors, inaccuracies and inconsistencies that make them almost useless for other investigators. In some cases several solutions, often very different among each other, are given for the same earthquake by different authors thus requiring a choice be made among them. We have tried to solve some of these problems, in building a comprehensive database, on a Microsoft ACCESS platform, including most of the mechanisms (about 6000 for the present version) published for the Italian region and more generally for the Mediterranean area. We tested the perpendicularity of nodal planes and/or P and T axes of all solutions and, when both axes and planes are given, even their mutual consistency. Moreover from the comparison of planes and axes we were able to detect and sometimes to correct misprints and other types of errors. All the parameters are recomputed uniformly and consistently, keeping track of all the corrections made. We also established an automatic procedure, based on several criteria, to choose the most ‘‘representative’’ solution when more than one is available for the same earthquake. The MS-ACCESS application also allows to making selections on the earthquake data, to display the plot of the mechanisms and to export data files suitable to be handled by graphic software and user written procedures
A database of revised fault plane solutions for Italy and surrounding regions
No full textThe analysis of fault plane solutions of earthquakes is carried out in most seismotectonic studies to characterize the tectonic deformation styles and to estimate strain and stress directions in the investigated areas. Nevertheless the data available in the literature, are reported with different formats and notations and, in most cases, only in papery form, so that they are not suitable to be handled by computer procedures and graphic packages. Sometimes the data are reported with typographical errors, inaccuracies and inconsistencies that make them almost useless for other investigators. In some cases several solutions, often very different among each other, are given for the same earthquake by different authors thus requiring a choice be made among them. We have tried to solve some of these problems, in building a comprehensive database, on a Microsoft ACCESS platform, including most of the mechanisms (presently about 5000) published for the Italian region and more generally for the Mediterranean area. We tested the perpendicularity of nodal planes and/or P and T axes of all solutions and, when both axes and planes are given, even their mutual consistency. Moreover from the comparison of planes and axes we were able to detect and sometimes to correct misprints and other types of errors. All the parameters are recomputed uniformly and consistently, keeping track of all the corrections made. We also established an automatic procedure, based on several criteria, to choose the most "representative" solution when more than one is available for the same earthquake. The MS-ACCESS application also allows to making selections on the earthquake data, to display the plot of the mechanisms and to export data files suitable to be handled by graphic software and user written procedures. © 2003 Elsevier Ltd. All rights reserved
FPSPACK: A package of FORTRAN subroutines to manage earthquake focal mechanism data
No full textEarthquakes fault plane solutions (FPSs) are routinely computed on the basis of various techniques and are reported in the literature with a wide range of formats and conventions. Although the equations relating the various parameters are well known and relatively simple, their practical application often arise to numerical singularities and indeterminations that sometimes are not well known by the authors and thus may result in wrong or inaccurate reporting of parameters. Such inaccuracies and mistakes affect about 40% of the published data we have examined to test our programs. Moreover the current use, in the seismological community, of at least two different coordinate systems to represent the Cartesian components of vectorial and tensorial quantities is a further cause of confusion. In order to simplify the management of such data, we have prepared a structured package of FORTRAN 77 subroutines performing almost all of the possible computations and conversions among different parameters and coordinate systems. The package has been extensively tested with the data of a revised database of FPS of Italy and surrounding regions (presented in a companion paper) as well as of CMT solutions included in the Harvard catalog. © 2003 Elsevier Ltd. All rights reserved
Vertigine Parossistica Posizionale e reperti Ecodoppler-sonografici: qualche utile indice prognostico?
No full textRhodolith assemblages from the lower Tortonian carbonate ramp of Menorca (Spain): Environmental and paleoclimatic implications
No full textLower Tortonian distally steepened carbonate ramp of Menorca mostly consists of foramol and rhodalgal facies deposited in inner-middle ramp, ramp slope and outer ramp settings. Red algae are abundant from the middle ramp to the lower part of the slope and their taxonomic assemblages are clearly related to the bathymetric position. Melobesioids percentage increases basinward, passing from 55.8% in the middle ramp to 97% in the toe of slope. Mastophoroids are more abundant in the middle ramp (43.1%) and decrease toward deeper paleoenvironments (1.2%). Lithophylloids and sporolithaceans appear as accessory components from the middle ramp to slope settings. The percentage of melobesioids and mastophoroids observed in the middle ramp suggest that growth of the rhodoliths started in a water depth below 10–20 m. The deepest occurrence of the rhodoliths is in the ramp slope environment, where the dominance of melobesioids and the low percentage of shallower-water subfamily suggests a water depth range of 70 to 100 m. Shape and structure of rhodoliths are indicative of high-energy conditions in all ramp settings and they do not reflect a decrease in hydrodynamic energy related to water depth increase. These conditions are related to the presence of unidirectional currents that produced cross-bedded grainstones existing in the middle ramp, ramp slope and at the toe of the ramp slope settings. The high percentage of mastophoroids in the shallowest environments and the presence of Lithoporella and Sporolithon in the coralline assemblages suggests that carbonate production took place in tropical waters
Efficacia e tollerabilità del trattamento steroideo per via sistemica in soggetti affetti da otite media secretiva.
No full textInhomogeneity of macroseismic intensities in italy and consequences for macroseismic magnitude estimation
Full text linkWe show that macroseismic intensities assessed in Italy in the last decade are not homogeneous with those of the previous periods. This is partly related to the recent adoption of the European Macroseismic Scale (EMS) in place of the Mercalli-Cancani-Sieberg (MCS) scale used up to about one decade ago. The underestimation of EMS with respect to MCS is about a half of a degree on average and, even more significant, if the MCS intensities are estimated according to the approach developed for the quick evaluations of damage by macroseismic seismologists of the Italian Department of Civil Protection. We also show the inhomogeneity over time of the average differences between instrumental and macroseismic magnitudes computed from intensity data, indicating an average overestimation of magnitudes of about 0.3 units for the instrumental ones before year 1960 and of about 0.2 units for the macroseismic ones after such date. This is consistent with previous studies that hypothesized the incorrect calibration of mechanical recording seismometers operating in Italy and in the surrounding countries before the introduction of the standard electromagnetic seismometers from the beginning of 1960s. For such reasons, the magnitudes of preinstrumental earthquakes in the Catalogo Parametrico dei Terremoti Italiani seismic catalog, used for the most recent seismic hazard assessment in Italy, might be overestimated, on average, by about 0.1-0.2 magnitude units
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