Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions
We constrained sedimentary basin structure using a nodal seismic array consisting of ten dense lines that overlie multiple basins in the northern Los Angeles area. The dense array consists of 758 seismic nodes, spaced ~250–300 m apart along linear transects, that recorded ground motions for 30–35 da...
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| Format: | Article |
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MDPI AG
2023-10-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/13/11/320 |
| _version_ | 1827639778205499392 |
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| author | Ritu Ghose Patricia Persaud Robert W. Clayton |
| author_facet | Ritu Ghose Patricia Persaud Robert W. Clayton |
| author_sort | Ritu Ghose |
| collection | DOAJ |
| description | We constrained sedimentary basin structure using a nodal seismic array consisting of ten dense lines that overlie multiple basins in the northern Los Angeles area. The dense array consists of 758 seismic nodes, spaced ~250–300 m apart along linear transects, that recorded ground motions for 30–35 days. We applied the receiver function (RF) technique to 16 teleseismic events to investigate basin structure. Primary basin-converted phases were identified in the RFs. A shear wave velocity model produced in a separate study using the same dataset was incorporated to convert the basin time arrivals to depth. The deepest part of the San Bernardino basin was identified near the Loma Linda fault at a depth of 2.4 km. Basin depths identified at pierce points for separate events reveal lateral changes in basin depth across distances of ~2–3 km near individual stations. A significant change in basin depth was identified within a small distance of ~4 km near the San Jacinto fault. The San Gabriel basin exhibited the largest basin depths of all three basins, with a maximum depth of 4.2 km. The high lateral resolution from the dense array helped to reveal more continuous structures and reduce uncertainties in the RFs interpretation. We discovered a more complex basin structure than previously identified. Our findings show that the basins’ core areas are not the deepest, and significant changes in basin depth were observed near some faults, including the San Jacinto fault, Fontana fault, Red Hill fault and Indian Hill fault. |
| first_indexed | 2024-03-09T16:47:51Z |
| format | Article |
| id | doaj.art-6333548e749948fc922e84b335f0f5df |
| institution | Directory Open Access Journal |
| issn | 2076-3263 |
| language | English |
| last_indexed | 2024-03-09T16:47:51Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Geosciences |
| spelling | doaj.art-6333548e749948fc922e84b335f0f5df2023-11-24T14:44:19ZengMDPI AGGeosciences2076-32632023-10-01131132010.3390/geosciences13110320Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver FunctionsRitu Ghose0Patricia Persaud1Robert W. Clayton2Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USADepartment of Geosciences, University of Arizona, Tucson, AZ 85721, USASeismological Laboratory, California Institute of Technology, Pasadena, CA 91125, USAWe constrained sedimentary basin structure using a nodal seismic array consisting of ten dense lines that overlie multiple basins in the northern Los Angeles area. The dense array consists of 758 seismic nodes, spaced ~250–300 m apart along linear transects, that recorded ground motions for 30–35 days. We applied the receiver function (RF) technique to 16 teleseismic events to investigate basin structure. Primary basin-converted phases were identified in the RFs. A shear wave velocity model produced in a separate study using the same dataset was incorporated to convert the basin time arrivals to depth. The deepest part of the San Bernardino basin was identified near the Loma Linda fault at a depth of 2.4 km. Basin depths identified at pierce points for separate events reveal lateral changes in basin depth across distances of ~2–3 km near individual stations. A significant change in basin depth was identified within a small distance of ~4 km near the San Jacinto fault. The San Gabriel basin exhibited the largest basin depths of all three basins, with a maximum depth of 4.2 km. The high lateral resolution from the dense array helped to reveal more continuous structures and reduce uncertainties in the RFs interpretation. We discovered a more complex basin structure than previously identified. Our findings show that the basins’ core areas are not the deepest, and significant changes in basin depth were observed near some faults, including the San Jacinto fault, Fontana fault, Red Hill fault and Indian Hill fault.https://www.mdpi.com/2076-3263/13/11/320basin amplificationreceiver functionnodal seismometersnorthern Los AngelesSan Bernardino basinSan Gabriel basin |
| spellingShingle | Ritu Ghose Patricia Persaud Robert W. Clayton Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions Geosciences basin amplification receiver function nodal seismometers northern Los Angeles San Bernardino basin San Gabriel basin |
| title | Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions |
| title_full | Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions |
| title_fullStr | Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions |
| title_full_unstemmed | Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions |
| title_short | Basin Structure for Earthquake Ground Motion Estimates in Urban Los Angeles Mapped with Nodal Receiver Functions |
| title_sort | basin structure for earthquake ground motion estimates in urban los angeles mapped with nodal receiver functions |
| topic | basin amplification receiver function nodal seismometers northern Los Angeles San Bernardino basin San Gabriel basin |
| url | https://www.mdpi.com/2076-3263/13/11/320 |
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