Abstract The Pacific ocean-bottom seismometer (OBS) Research into Convecting Asthenosphere (ORCA) experiment deployed two 30-station seismic arrays between 2018 and 2020—a US contribution to the international PacificArray project. “Young ORCA” array on ?40 Ma central seafloor had a ?68% data recovery rate, whereas “Old ?120 southwest ?80% rate. We detail here quality, spectral characteristics, ...

Extensive intraplate volcanism in the East Asia regions, including Dokdo and Ulleungdo (DU), occurred due to extensional stress field during Cenozoic era. However, origin of magmatism is still controversial. Here we report new results helium isotopes olivine clinopyroxene phenocrysts as well major trace element compositions from DU basalts order determine magmas provide insights into mantle dyn...

Multi-ring basins represent some of the largest, oldest, rarest and, therefore, least understood impact crater structures. Various theories have been put forward to explain their formation; there is currently, however, no consensus. Here, numerical modeling is used to investigate the onset of multi-ring basin formation on the Moon using two thermal profiles suitable for the lunar basin-forming ...

a r t i c l e i n f o a b s t r a c t Keywords: lithosphere–asthenosphere boundary Northeastern margin of the Tibetan Plateau Receiver functions Whether or not the Asian lithosphere has underthrusted beneath the Tibetan Plateau is important for understanding the mechanisms of the plateau's growth. Using data from the permanent seismic stations in northeastern Tibetan Plateau, we studied seismic...

It is commonly thought hot diapiric flows prevail in the mantle wedge above the subducting slab. However, hydration and partial melting along the slab can create a situation in which a Rayleigh-Taylor instability can develop at the top of a cold subducting slab. We have modelled numerically with a high-resolution 2-D regional model this parodoxically interesting geological phenomenon in which r...

Long records of teleseismic observations accumulated at permanent seismic stations Harvard, MA; Palisades, NY; and Standing Stone, PA, in eastern North America are inverted for vertical distribution of anisotropic parameters. High-resolution anisotropy-aware P wave receiver function analysis and multiple-layer core-refracted SKS waveform modeling favor more than one layer of anisotropy beneath ...

The Earth is likely to have acquired most of its water during accretion. Internal heat of planetesimals by short-lived radioisotopes would have caused some water loss, but impacts into planetesimals were insufficiently energetic to produce further drying. Water is thought to be critical for the development of plate tectonics, because it lowers viscosities in the asthenosphere, enabling subducti...