Field and synthetic waveform tests on using large-offset seismic streamer data to derive shallow seabed shear-wave velocity and geotechnical properties

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F22%3A00558829" target="_blank" >RIV/67985530:_____/22:00558829 - isvavai.cz</a>

Výsledek na webu

<a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021EA002196" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021EA002196</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2021EA002196" target="_blank" >10.1029/2021EA002196</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Field and synthetic waveform tests on using large-offset seismic streamer data to derive shallow seabed shear-wave velocity and geotechnical properties

Popis výsledku v původním jazyce

Characterizing properties of marine subsurface sediment helps with siting for offshore infrastructure. Shear-wave velocity (V-s) provides information on the geotechnical properties of the seabed. We present our initial efforts to obtain a detailed two-dimensional model of V-s for a large-offset multi-channel seismic (MCS) transect collected in shallow waters across the Taiwan Strait using surface waves excited by a large volume airgun. We derived the dispersion curves of the Scholte waves along the 37.5-km-long transect using the phase-shift method and then conducted multimodal inversion to obtain a V-s model down to a depth of 150 m. To estimate the dynamic Poisson's ratio across the transect, we combined the V-s model with a compressional wave velocity model derived from the traditional MCS semblance velocity analysis. Lastly, we approximated the seismic attenuation of the profile. Our results show a large lateral variation in shear-wave velocity. In the north, a low-velocity zone with shear-wave velocities of about 150 m/s was identified, while in the south, the shear-wave velocity was found to be 300 m/s. With synthetic data, several sensitivity tests were performed to derive optimal parameters for offshore large-offset streamer data. We particularly focused on the depth of the streamer and source and the water depth in combination with different seabed properties. Our results show that we can robustly derive the shear-wave velocity, along with the Poisson's ratio, using large-offset streamer data elsewhere based on the criteria we have tested using field and synthetic data sets.

Název v anglickém jazyce

Field and synthetic waveform tests on using large-offset seismic streamer data to derive shallow seabed shear-wave velocity and geotechnical properties

Popis výsledku anglicky

Characterizing properties of marine subsurface sediment helps with siting for offshore infrastructure. Shear-wave velocity (V-s) provides information on the geotechnical properties of the seabed. We present our initial efforts to obtain a detailed two-dimensional model of V-s for a large-offset multi-channel seismic (MCS) transect collected in shallow waters across the Taiwan Strait using surface waves excited by a large volume airgun. We derived the dispersion curves of the Scholte waves along the 37.5-km-long transect using the phase-shift method and then conducted multimodal inversion to obtain a V-s model down to a depth of 150 m. To estimate the dynamic Poisson's ratio across the transect, we combined the V-s model with a compressional wave velocity model derived from the traditional MCS semblance velocity analysis. Lastly, we approximated the seismic attenuation of the profile. Our results show a large lateral variation in shear-wave velocity. In the north, a low-velocity zone with shear-wave velocities of about 150 m/s was identified, while in the south, the shear-wave velocity was found to be 300 m/s. With synthetic data, several sensitivity tests were performed to derive optimal parameters for offshore large-offset streamer data. We particularly focused on the depth of the streamer and source and the water depth in combination with different seabed properties. Our results show that we can robustly derive the shear-wave velocity, along with the Poisson's ratio, using large-offset streamer data elsewhere based on the criteria we have tested using field and synthetic data sets.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10507 - Volcanology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Earth and Space Science

ISSN

2333-5084

e-ISSN

2333-5084

Svazek periodika

9

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

e2021EA002196

Kód UT WoS článku

000815218700001

EID výsledku v databázi Scopus

2-s2.0-85133099878