The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform

Anna Gabàs - One of the best experts on this subject based on the ideXlab platform.

  • Application of geophysical techniques to support Geological Mapping projects
    First Break, 2016
    Co-Authors: Beatriz Benjumea, Albert Macau, Anna Gabàs, Sara Figueras, Fabian Bellmunt
    Abstract:

    Better and more detailed information on the bedrock and near-surface geology is needed to assist Geological risk assessments, efficient use of water resources or management of rapidly growing regions. Since 2007, the Cartographic and Geological Institute of Catalonia (ICGC) has developed a Geological Mapping programme, which includes information related to hydrogeology, urban geology or Geological risks among others. Within this framework, geophysical techniques make an important contribution refining Geological Mapping by adding subsoil information to traditional Geological data. In this work, we present two studies carried out by ICGC in order to map bedrock geometry or to characterize near-surface sediments in areas with scarce borehole information. The first example of this support focuses on the combination of passive and active geophysical techniques in order to image the Quaternary/Neogene boundary, the bedrock top and to locate faults or the Geological map of the Girona urban area (NE of Spain). The second case study shows the potential of reprocessing vintage seismic oil datasets to increase knowledge of the near-surface Geological structure in a Neogene Basin located north of Girona (Emporda Basin). The reprocessed seismic reflection image of the first km depth has been interpreted using the refraction velocity model and passive seismic information as constraints. The main objectives are to recover bedrock geometry and structure as well as fault imaging, which are critical for Geological Mapping projects. The common pattern of the methodologies applied to each case is the integration of different geophysical datasets and the use of both active and passive techniques.

  • Combination of Geophysical Methods to Support Urban Geological Mapping
    Surveys in Geophysics, 2014
    Co-Authors: Anna Gabàs, Albert Macau, Sara Figueras, Beatriz Benjumea, Fabian Bellmunt, Miquel Vila
    Abstract:

    Urban Geological Mapping is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban Geological hazards. Geophysics can have a pivotal role to yield subsurface information in urban areas provided that geophysical methods are capable of dealing with challenges related to these scenarios (e.g., low signal-to-noise ratio or special logistical arrangements). With this principal aim, a specific methodology is developed to characterize lithological changes, to image fault zones and to delineate basin geometry in the urban areas. The process uses the combination of passive and active techniques as complementary data: controlled source audio-magnetotelluric method (CSAMT), magnetotelluric method (MT), microtremor H/V analysis and ambient noise array measurements to overcome the limitations of traditional geophysical methodology. This study is focused in Girona and Salt surrounding areas (NE of Spain) where some uncertainties in subsurface knowledge (maps of bedrock depth and the isopach maps of thickness of quaternary sediments) need to be resolved to carry out the 1:5000 urban Geological Mapping. These parameters can be estimated using this proposed methodology. (1) Acoustic impedance contrast between Neogene sediments and Paleogene or Paleozoic bedrock is detected with microtremor H/V analysis that provides the soil resonance frequency. The minimum value obtained is 0.4 Hz in Salt city, and the maximum value is the 9.5 Hz in Girona city. The result of this first method is a fast scanner of the geometry of basement. (2) Ambient noise array constrains the bedrock depth using the measurements of shear-wave velocity of soft soil. (3) Finally, the electrical resistivity models contribute with a good description of lithological changes and fault imaging. The conductive materials (1-100 Ωm) are associated with Neogene Basin composed by unconsolidated detrital sediments; medium resistive materials (100-400 Ωm) correspond to Paleogene, and resistive materials (600-1,000 Ωm) are related with complex basement, granite of Paleozoic. The Neogene basin-basement boundary is constrained between surface and 500 m depth, approximately. The new geophysical methodology presented is an optimized and fast tool to refine Geological Mapping by adding 2D information to traditional Geological data and improving the knowledge of subsoil. [ABSTRACT FROM AUTHOR]

Fabian Bellmunt - One of the best experts on this subject based on the ideXlab platform.

  • Application of geophysical techniques to support Geological Mapping projects
    First Break, 2016
    Co-Authors: Beatriz Benjumea, Albert Macau, Anna Gabàs, Sara Figueras, Fabian Bellmunt
    Abstract:

    Better and more detailed information on the bedrock and near-surface geology is needed to assist Geological risk assessments, efficient use of water resources or management of rapidly growing regions. Since 2007, the Cartographic and Geological Institute of Catalonia (ICGC) has developed a Geological Mapping programme, which includes information related to hydrogeology, urban geology or Geological risks among others. Within this framework, geophysical techniques make an important contribution refining Geological Mapping by adding subsoil information to traditional Geological data. In this work, we present two studies carried out by ICGC in order to map bedrock geometry or to characterize near-surface sediments in areas with scarce borehole information. The first example of this support focuses on the combination of passive and active geophysical techniques in order to image the Quaternary/Neogene boundary, the bedrock top and to locate faults or the Geological map of the Girona urban area (NE of Spain). The second case study shows the potential of reprocessing vintage seismic oil datasets to increase knowledge of the near-surface Geological structure in a Neogene Basin located north of Girona (Emporda Basin). The reprocessed seismic reflection image of the first km depth has been interpreted using the refraction velocity model and passive seismic information as constraints. The main objectives are to recover bedrock geometry and structure as well as fault imaging, which are critical for Geological Mapping projects. The common pattern of the methodologies applied to each case is the integration of different geophysical datasets and the use of both active and passive techniques.

  • Combination of Geophysical Methods to Support Urban Geological Mapping
    Surveys in Geophysics, 2014
    Co-Authors: Anna Gabàs, Albert Macau, Sara Figueras, Beatriz Benjumea, Fabian Bellmunt, Miquel Vila
    Abstract:

    Urban Geological Mapping is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban Geological hazards. Geophysics can have a pivotal role to yield subsurface information in urban areas provided that geophysical methods are capable of dealing with challenges related to these scenarios (e.g., low signal-to-noise ratio or special logistical arrangements). With this principal aim, a specific methodology is developed to characterize lithological changes, to image fault zones and to delineate basin geometry in the urban areas. The process uses the combination of passive and active techniques as complementary data: controlled source audio-magnetotelluric method (CSAMT), magnetotelluric method (MT), microtremor H/V analysis and ambient noise array measurements to overcome the limitations of traditional geophysical methodology. This study is focused in Girona and Salt surrounding areas (NE of Spain) where some uncertainties in subsurface knowledge (maps of bedrock depth and the isopach maps of thickness of quaternary sediments) need to be resolved to carry out the 1:5000 urban Geological Mapping. These parameters can be estimated using this proposed methodology. (1) Acoustic impedance contrast between Neogene sediments and Paleogene or Paleozoic bedrock is detected with microtremor H/V analysis that provides the soil resonance frequency. The minimum value obtained is 0.4 Hz in Salt city, and the maximum value is the 9.5 Hz in Girona city. The result of this first method is a fast scanner of the geometry of basement. (2) Ambient noise array constrains the bedrock depth using the measurements of shear-wave velocity of soft soil. (3) Finally, the electrical resistivity models contribute with a good description of lithological changes and fault imaging. The conductive materials (1-100 Ωm) are associated with Neogene Basin composed by unconsolidated detrital sediments; medium resistive materials (100-400 Ωm) correspond to Paleogene, and resistive materials (600-1,000 Ωm) are related with complex basement, granite of Paleozoic. The Neogene basin-basement boundary is constrained between surface and 500 m depth, approximately. The new geophysical methodology presented is an optimized and fast tool to refine Geological Mapping by adding 2D information to traditional Geological data and improving the knowledge of subsoil. [ABSTRACT FROM AUTHOR]

Miquel Vila - One of the best experts on this subject based on the ideXlab platform.

  • Combination of Geophysical Methods to Support Urban Geological Mapping
    Surveys in Geophysics, 2014
    Co-Authors: Anna Gabàs, Albert Macau, Sara Figueras, Beatriz Benjumea, Fabian Bellmunt, Miquel Vila
    Abstract:

    Urban Geological Mapping is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban Geological hazards. Geophysics can have a pivotal role to yield subsurface information in urban areas provided that geophysical methods are capable of dealing with challenges related to these scenarios (e.g., low signal-to-noise ratio or special logistical arrangements). With this principal aim, a specific methodology is developed to characterize lithological changes, to image fault zones and to delineate basin geometry in the urban areas. The process uses the combination of passive and active techniques as complementary data: controlled source audio-magnetotelluric method (CSAMT), magnetotelluric method (MT), microtremor H/V analysis and ambient noise array measurements to overcome the limitations of traditional geophysical methodology. This study is focused in Girona and Salt surrounding areas (NE of Spain) where some uncertainties in subsurface knowledge (maps of bedrock depth and the isopach maps of thickness of quaternary sediments) need to be resolved to carry out the 1:5000 urban Geological Mapping. These parameters can be estimated using this proposed methodology. (1) Acoustic impedance contrast between Neogene sediments and Paleogene or Paleozoic bedrock is detected with microtremor H/V analysis that provides the soil resonance frequency. The minimum value obtained is 0.4 Hz in Salt city, and the maximum value is the 9.5 Hz in Girona city. The result of this first method is a fast scanner of the geometry of basement. (2) Ambient noise array constrains the bedrock depth using the measurements of shear-wave velocity of soft soil. (3) Finally, the electrical resistivity models contribute with a good description of lithological changes and fault imaging. The conductive materials (1-100 Ωm) are associated with Neogene Basin composed by unconsolidated detrital sediments; medium resistive materials (100-400 Ωm) correspond to Paleogene, and resistive materials (600-1,000 Ωm) are related with complex basement, granite of Paleozoic. The Neogene basin-basement boundary is constrained between surface and 500 m depth, approximately. The new geophysical methodology presented is an optimized and fast tool to refine Geological Mapping by adding 2D information to traditional Geological data and improving the knowledge of subsoil. [ABSTRACT FROM AUTHOR]

Beatriz Benjumea - One of the best experts on this subject based on the ideXlab platform.

  • Application of geophysical techniques to support Geological Mapping projects
    First Break, 2016
    Co-Authors: Beatriz Benjumea, Albert Macau, Anna Gabàs, Sara Figueras, Fabian Bellmunt
    Abstract:

    Better and more detailed information on the bedrock and near-surface geology is needed to assist Geological risk assessments, efficient use of water resources or management of rapidly growing regions. Since 2007, the Cartographic and Geological Institute of Catalonia (ICGC) has developed a Geological Mapping programme, which includes information related to hydrogeology, urban geology or Geological risks among others. Within this framework, geophysical techniques make an important contribution refining Geological Mapping by adding subsoil information to traditional Geological data. In this work, we present two studies carried out by ICGC in order to map bedrock geometry or to characterize near-surface sediments in areas with scarce borehole information. The first example of this support focuses on the combination of passive and active geophysical techniques in order to image the Quaternary/Neogene boundary, the bedrock top and to locate faults or the Geological map of the Girona urban area (NE of Spain). The second case study shows the potential of reprocessing vintage seismic oil datasets to increase knowledge of the near-surface Geological structure in a Neogene Basin located north of Girona (Emporda Basin). The reprocessed seismic reflection image of the first km depth has been interpreted using the refraction velocity model and passive seismic information as constraints. The main objectives are to recover bedrock geometry and structure as well as fault imaging, which are critical for Geological Mapping projects. The common pattern of the methodologies applied to each case is the integration of different geophysical datasets and the use of both active and passive techniques.

  • Combination of Geophysical Methods to Support Urban Geological Mapping
    Surveys in Geophysics, 2014
    Co-Authors: Anna Gabàs, Albert Macau, Sara Figueras, Beatriz Benjumea, Fabian Bellmunt, Miquel Vila
    Abstract:

    Urban Geological Mapping is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban Geological hazards. Geophysics can have a pivotal role to yield subsurface information in urban areas provided that geophysical methods are capable of dealing with challenges related to these scenarios (e.g., low signal-to-noise ratio or special logistical arrangements). With this principal aim, a specific methodology is developed to characterize lithological changes, to image fault zones and to delineate basin geometry in the urban areas. The process uses the combination of passive and active techniques as complementary data: controlled source audio-magnetotelluric method (CSAMT), magnetotelluric method (MT), microtremor H/V analysis and ambient noise array measurements to overcome the limitations of traditional geophysical methodology. This study is focused in Girona and Salt surrounding areas (NE of Spain) where some uncertainties in subsurface knowledge (maps of bedrock depth and the isopach maps of thickness of quaternary sediments) need to be resolved to carry out the 1:5000 urban Geological Mapping. These parameters can be estimated using this proposed methodology. (1) Acoustic impedance contrast between Neogene sediments and Paleogene or Paleozoic bedrock is detected with microtremor H/V analysis that provides the soil resonance frequency. The minimum value obtained is 0.4 Hz in Salt city, and the maximum value is the 9.5 Hz in Girona city. The result of this first method is a fast scanner of the geometry of basement. (2) Ambient noise array constrains the bedrock depth using the measurements of shear-wave velocity of soft soil. (3) Finally, the electrical resistivity models contribute with a good description of lithological changes and fault imaging. The conductive materials (1-100 Ωm) are associated with Neogene Basin composed by unconsolidated detrital sediments; medium resistive materials (100-400 Ωm) correspond to Paleogene, and resistive materials (600-1,000 Ωm) are related with complex basement, granite of Paleozoic. The Neogene basin-basement boundary is constrained between surface and 500 m depth, approximately. The new geophysical methodology presented is an optimized and fast tool to refine Geological Mapping by adding 2D information to traditional Geological data and improving the knowledge of subsoil. [ABSTRACT FROM AUTHOR]

Albert Macau - One of the best experts on this subject based on the ideXlab platform.

  • Application of geophysical techniques to support Geological Mapping projects
    First Break, 2016
    Co-Authors: Beatriz Benjumea, Albert Macau, Anna Gabàs, Sara Figueras, Fabian Bellmunt
    Abstract:

    Better and more detailed information on the bedrock and near-surface geology is needed to assist Geological risk assessments, efficient use of water resources or management of rapidly growing regions. Since 2007, the Cartographic and Geological Institute of Catalonia (ICGC) has developed a Geological Mapping programme, which includes information related to hydrogeology, urban geology or Geological risks among others. Within this framework, geophysical techniques make an important contribution refining Geological Mapping by adding subsoil information to traditional Geological data. In this work, we present two studies carried out by ICGC in order to map bedrock geometry or to characterize near-surface sediments in areas with scarce borehole information. The first example of this support focuses on the combination of passive and active geophysical techniques in order to image the Quaternary/Neogene boundary, the bedrock top and to locate faults or the Geological map of the Girona urban area (NE of Spain). The second case study shows the potential of reprocessing vintage seismic oil datasets to increase knowledge of the near-surface Geological structure in a Neogene Basin located north of Girona (Emporda Basin). The reprocessed seismic reflection image of the first km depth has been interpreted using the refraction velocity model and passive seismic information as constraints. The main objectives are to recover bedrock geometry and structure as well as fault imaging, which are critical for Geological Mapping projects. The common pattern of the methodologies applied to each case is the integration of different geophysical datasets and the use of both active and passive techniques.

  • Combination of Geophysical Methods to Support Urban Geological Mapping
    Surveys in Geophysics, 2014
    Co-Authors: Anna Gabàs, Albert Macau, Sara Figueras, Beatriz Benjumea, Fabian Bellmunt, Miquel Vila
    Abstract:

    Urban Geological Mapping is a key to assist management of new developed areas, conversion of current urban areas or assessment of urban Geological hazards. Geophysics can have a pivotal role to yield subsurface information in urban areas provided that geophysical methods are capable of dealing with challenges related to these scenarios (e.g., low signal-to-noise ratio or special logistical arrangements). With this principal aim, a specific methodology is developed to characterize lithological changes, to image fault zones and to delineate basin geometry in the urban areas. The process uses the combination of passive and active techniques as complementary data: controlled source audio-magnetotelluric method (CSAMT), magnetotelluric method (MT), microtremor H/V analysis and ambient noise array measurements to overcome the limitations of traditional geophysical methodology. This study is focused in Girona and Salt surrounding areas (NE of Spain) where some uncertainties in subsurface knowledge (maps of bedrock depth and the isopach maps of thickness of quaternary sediments) need to be resolved to carry out the 1:5000 urban Geological Mapping. These parameters can be estimated using this proposed methodology. (1) Acoustic impedance contrast between Neogene sediments and Paleogene or Paleozoic bedrock is detected with microtremor H/V analysis that provides the soil resonance frequency. The minimum value obtained is 0.4 Hz in Salt city, and the maximum value is the 9.5 Hz in Girona city. The result of this first method is a fast scanner of the geometry of basement. (2) Ambient noise array constrains the bedrock depth using the measurements of shear-wave velocity of soft soil. (3) Finally, the electrical resistivity models contribute with a good description of lithological changes and fault imaging. The conductive materials (1-100 Ωm) are associated with Neogene Basin composed by unconsolidated detrital sediments; medium resistive materials (100-400 Ωm) correspond to Paleogene, and resistive materials (600-1,000 Ωm) are related with complex basement, granite of Paleozoic. The Neogene basin-basement boundary is constrained between surface and 500 m depth, approximately. The new geophysical methodology presented is an optimized and fast tool to refine Geological Mapping by adding 2D information to traditional Geological data and improving the knowledge of subsoil. [ABSTRACT FROM AUTHOR]