Adjoint-state differential arrival time tomography
The recently developed adjoint-state traveltime tomography (ATT) method offers an alternative approach to conduct traveltime tomography without the need for ray tracing or waveform modelling. Instead, it utilizes the eikonal equation to depict the minimal traveltime field from an earthquake location...
| Main Authors: | , , , |
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| Format: | Journal Article |
| Language: | English |
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2024
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| Online Access: | https://hdl.handle.net/10356/173695 |
| _version_ | 1824456087064018944 |
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| author | Tong, Ping Li, Tianjue Chen, Jing Nagaso,Masaru |
| author2 | School of Physical and Mathematical Sciences |
| author_facet | School of Physical and Mathematical Sciences Tong, Ping Li, Tianjue Chen, Jing Nagaso,Masaru |
| author_sort | Tong, Ping |
| collection | NTU |
| description | The recently developed adjoint-state traveltime tomography (ATT) method offers an alternative approach to conduct traveltime tomography without the need for ray tracing or waveform modelling. Instead, it utilizes the eikonal equation to depict the minimal traveltime field from an earthquake location to any position in the computational domain. The process of tomographic inversion is formulated as an optimization problem with the goal of minimizing the difference between observed and theoretical first arrival times, which is subsequently solved using the efficient adjoint method. One advantage of differential arrival time data is that it cancels or reduces the influence of common factors, making it more sensitive to a specific subset of model parameters compared to first arrival times. To take advantage of this property, two variants of the ATT method are derived to determine velocity structure and earthquake locations in this study. The first variant, adjoint-state common-source differential arrival time tomography (ATT-CS), uses common-source differential arrival times; while the second variant, adjoint-state common-receiver differential arrival time tomography (ATT-CR), inverts common-receiver differential arrival times. Numerical examples demonstrate that the ATT-CS method is a valuable tool for imaging receiver-side fine-scale velocity structures. Conversely, the ATT-CR method is well suited for resolving source-side velocity structures. Differential arrival times also place constraints on earthquake locations. Compared to common-source differential arrival times, common-receiver differential arrival times are less sensitive to velocity errors and suitable for earthquake location determination. Both common-source and common-receiver differential arrival times are considered first-order differential arrival times. To demonstrate the ease with which the ATT method can be extended to higher-order differential arrival times, we also derive the adjoint-state second-order differential arrival time tomography method. Finally, we discuss how the adjoint-state tomography methods address multipathing. |
| first_indexed | 2025-02-19T03:48:31Z |
| format | Journal Article |
| id | ntu-10356/173695 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2025-02-19T03:48:31Z |
| publishDate | 2024 |
| record_format | dspace |
| spelling | ntu-10356/1736952024-02-26T15:35:41Z Adjoint-state differential arrival time tomography Tong, Ping Li, Tianjue Chen, Jing Nagaso,Masaru School of Physical and Mathematical Sciences Asian School of the Environment Earth Observatory of Singapore Mathematical Sciences Inverse theory Seismic tomography The recently developed adjoint-state traveltime tomography (ATT) method offers an alternative approach to conduct traveltime tomography without the need for ray tracing or waveform modelling. Instead, it utilizes the eikonal equation to depict the minimal traveltime field from an earthquake location to any position in the computational domain. The process of tomographic inversion is formulated as an optimization problem with the goal of minimizing the difference between observed and theoretical first arrival times, which is subsequently solved using the efficient adjoint method. One advantage of differential arrival time data is that it cancels or reduces the influence of common factors, making it more sensitive to a specific subset of model parameters compared to first arrival times. To take advantage of this property, two variants of the ATT method are derived to determine velocity structure and earthquake locations in this study. The first variant, adjoint-state common-source differential arrival time tomography (ATT-CS), uses common-source differential arrival times; while the second variant, adjoint-state common-receiver differential arrival time tomography (ATT-CR), inverts common-receiver differential arrival times. Numerical examples demonstrate that the ATT-CS method is a valuable tool for imaging receiver-side fine-scale velocity structures. Conversely, the ATT-CR method is well suited for resolving source-side velocity structures. Differential arrival times also place constraints on earthquake locations. Compared to common-source differential arrival times, common-receiver differential arrival times are less sensitive to velocity errors and suitable for earthquake location determination. Both common-source and common-receiver differential arrival times are considered first-order differential arrival times. To demonstrate the ease with which the ATT method can be extended to higher-order differential arrival times, we also derive the adjoint-state second-order differential arrival time tomography method. Finally, we discuss how the adjoint-state tomography methods address multipathing. Ministry of Education (MOE) National Research Foundation (NRF) Published version This work was supported by the Ministry of Education, Singapore, under its MOE AcRF Tier 1 grant (RG86/22). PT and TL were also supported by the National Research Foundation Singapore and the Ministry of Education, Singapore, under the Research Centres of Excellence initiative (04MNS001953A620). 2024-02-23T00:42:55Z 2024-02-23T00:42:55Z 2024 Journal Article Tong, P., Li, T., Chen, J. & Nagaso, M. (2024). Adjoint-state differential arrival time tomography. Geophysical Journal International, 236(1), 139-160. https://dx.doi.org/10.1093/gji/ggad416 0956-540X https://hdl.handle.net/10356/173695 10.1093/gji/ggad416 2-s2.0-85177749112 1 236 139 160 en RG86/22 04MNS001953A620 Geophysical Journal International © 2023 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. application/pdf |
| spellingShingle | Mathematical Sciences Inverse theory Seismic tomography Tong, Ping Li, Tianjue Chen, Jing Nagaso,Masaru Adjoint-state differential arrival time tomography |
| title | Adjoint-state differential arrival time tomography |
| title_full | Adjoint-state differential arrival time tomography |
| title_fullStr | Adjoint-state differential arrival time tomography |
| title_full_unstemmed | Adjoint-state differential arrival time tomography |
| title_short | Adjoint-state differential arrival time tomography |
| title_sort | adjoint state differential arrival time tomography |
| topic | Mathematical Sciences Inverse theory Seismic tomography |
| url | https://hdl.handle.net/10356/173695 |
| work_keys_str_mv | AT tongping adjointstatedifferentialarrivaltimetomography AT litianjue adjointstatedifferentialarrivaltimetomography AT chenjing adjointstatedifferentialarrivaltimetomography AT nagasomasaru adjointstatedifferentialarrivaltimetomography |