Seismic structure of a Tethyan back-arc: Transdimensional ambient noise tomography of the Black Sea lithosphere

Petrescu, Laura; Borleanu, Felix; Plăcintă, Anica Otilia

doi:10.1016/j.pepi.2022.106854

Cited by 6 publications

(3 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…25 km both in the western and eastern basins with a ca. 40 km thick crust below the Mid Black-Sea Ridge (Petrescu et al, 2022). This study imaged a contrasting lithospheric structure below the two basins with seismic velocities slower below the Western Black Sea.…”

Section: #25 Black Seamentioning

confidence: 70%

“…The nature of the crust in the Black Sea is debated (Nikishin et al, 2003;Starostenko et al, 2004;Minshull et al, 2005;Yegorova and Gobarenko, 2010;Nikishin et al, 2015;Stephenson and Stovba, 2021;Petrescu et al, 2022) and the contrasting models infer that its deep basins may have formed on an extended cratonic lithosphere or that they may preserve trapped fragments of the Tethyan oceanic lithosphere. Geodynamic interpretations of recent high-resolution seismic reflection surveys in the entire Black Sea basin, which constrained the structure of the sedimentary cover and the Moho interface, propose that both the Western and Eastern Black Sea deep basins have oceanic crust in their central parts, surrounded by thinned rifted continental crust towards the coasts (Nikishin et al, 2015).…”

Section: #25 Black Seamentioning

confidence: 99%

See 1 more Smart Citation

Back-arc basins: A global view from geophysical synthesis and analysis

Artemieva

2023

Preprint

View full text Add to dashboard Cite

<p>This global study of 31 off-shore back-arc basins (BABs) identifies their principal characteristics based on a broad spectrum of geophysical and subduction-related parameters. My synthesis is used to identify trends in the evolution of BABs for improving our understanding of subduction systems in general. The analysis, based on the present plate configuration, demonstrates that geophysical characteristics and fate of the BABs are essentially controlled by the tectonic type of the overriding plate, which controls the lithosphere thermo-compositional structure and rheology. The type of the plate governs the length of the extensional zone in back-arc settings along the trench, the efficiency of lithosphere stretching, and the crustal structure, buoyancy and bathymetry of the BABs. Subduction dip angle apparently controls the location of the slab melting zone and the efficiency of slab roll-back with feedback links to other parameters. By the tectonic nature of the overriding plate (the downgoing plate is always oceanic) the back-arc basins are split into active BABs formed by ocean-ocean, arc-ocean, and continent-ocean convergence, and extinct back-arc basins. By geophysical characteristics, BABs formed on continental plates are subdivided into active BABs with and without seafloor spreading, and extinct BABs are subdivided into the Pacific BABs, possibly formed on oceanic plates, and the non-Pacific BABs with reworked continental or arc fragments. Six types of BABs are distinctly different. Extension of the overriding oceanic plate above a steeply dipping old oceanic plate, preferentially subducting nearly westwards, forms large deep back-arc basins with a thin oceanic- type crust. In contrast, BABs on the overriding continental or arc plates form at small opening rates and often by shallow subduction of younger oceanic plates with a random subduction orientation; these BABs have small sizes, shallow bathymetry, and hyperextended or transitional ~20 km thick arc- or continental-type crust typical of passive margins. The presence of a 2&#8211;5 km thick high-Vp lowermost crustal layer, characteristic of BABs in all settings, indicates the importance of magmatic underplating in the crustal growth. Conditions required for the initiation of a back-arc basin and transition from stretching to seafloor opening depend on the nature of the overriding plate. BABs formed on oceanic plates always evolve to seafloor spreading. BABs formed on continental or arc plates require long spreading duration with large (>8 cm/y) opening rates and a large crustal thinning factor of 2.8&#8211;5.0 to progress from crustal extension to seafloor spreading. On the present Earth such transition does not happen in the BABs formed behind a shallow subduction (<45o) of a young (<40 My) oceanic plate. The nature of the overriding plate also determines the fate of back-arc basins after termination of lithosphere extension: the extinct Pacific BABs with oceanic-type crust evolve towards deep old &#8220;normal&#8221; oceans, while the shallow non-Pacific BABs with low heat flow and thick crust are likely to preserve their continental or arc affinity. BABs do not follow the oceanic cooling plate model predictions. Distinctly different geophysical signatures for mid-ocean ridge spreading and for back-arc seafloor spreading are caused by principally different dynamics. https://doi.org/10.1016/j.earscirev.2022.104242</p>

show abstract

Section: #25 Black Seamentioning

confidence: 70%

Section: #25 Black Seamentioning

confidence: 99%

Back-arc basins: A global view from geophysical synthesis and analysis

Artemieva

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…The seismic beacon signal spectrum had to be calculated from several million samples for good resolution. The methodology is based on the processing of long time series of continuous seismic noise, e.g., [ 22 , 23 , 24 , 25 , 26 ] or from groundwater level variations [ 27 ].…”

Section: Resultsmentioning

confidence: 99%

Seismic Beacon—A New Instrument for Detection of Changes in Rock Massif

Lukešová,

Málek

2023

Sensors

View full text Add to dashboard Cite

The seismic beacon is a new instrument that allows for the measurement of changes in a rock massif with high sensitivity. It is based on effects, which affect the propagation of harmonic seismic waves generated continuously with stable and precise frequency and amplitude. These seismic waves are registered by a system of seismic stations. The amplitude of the seismic signal is very small, and it is normally hidden in a seismic noise. Special techniques are applied to increase the signal-to-noise ratio. In 2020, the first prototype of the seismic beacon was constructed in a laboratory, and field tests were performed in 2022 and 2023. During the tests, the changes in spectral amplitude and phase of seismic waves were detected, which is interpreted as the changes in material properties. These measurements testified the basic functionality of the device. The seismic beacon has been developed primarily for the detection of critical stress before an earthquake, which is manifested by non-linear effects such as higher harmonics generation. In addition, it could be used, for example, in the detection of magma movements, groundwater level changes, changes in hydrocarbon saturation in rocks during the extraction of oil and natural gas, or the penetration of gases and liquids into the earth’s crust.

show abstract