TY - JOUR A1 - Le Friant, A. A1 - Ishizuka, O. A1 - Boudon, G. A1 - Palmer, M. R. A1 - Talling, P. J. A1 - Villemant, B. A1 - Adachi, T. A1 - Aljahdali, M. A1 - Breitkreuz, C. A1 - Brunet, M. A1 - Caron, B. A1 - Coussens, M. A1 - Deplus, C. A1 - Endo, D. A1 - Feuillet, N. A1 - Fraas, A. J. A1 - Fujinawa, A. A1 - Hart, M. B. A1 - Hatfield, R. G. A1 - Hornbach, M. A1 - Jutzeler, M. A1 - Kataoka, K. S. A1 - Komorowski, J. -C. A1 - Lebas, E. A1 - Lafuerza, S. A1 - Maeno, F. A1 - Manga, M. A1 - Martinez-Colon, M. A1 - McCanta, M. A1 - Morgan, S. A1 - Saito, T. A1 - Slagle, A. A1 - Sparks, S. A1 - Stinton, A. A1 - Stroncik, Nicole A1 - Subramanyam, K. S. V. A1 - Tamura, Yui A1 - Trofimovs, J. A1 - Voight, B. A1 - Wall-Palmer, D. A1 - Wang, F. A1 - Watt, S. F. L. T1 - Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340 JF - Geochemistry, geophysics, geosystems N2 - IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition and origin of those deposits. Sites U1394, U1399, and U1400 that penetrated landslide deposits recovered exclusively seafloor sediment, comprising mainly turbidites and hemipelagic deposits, and lacked debris avalanche deposits. This supports the concepts that i/ volcanic debris avalanches tend to stop at the slope break, and ii/ widespread and voluminous failures of preexisting low-gradient seafloor sediment can be triggered by initial emplacement of material from the volcano. Offshore Martinique (U1399 and 1400), the landslide deposits comprised blocks of parallel strata that were tilted or microfaulted, sometimes separated by intervals of homogenized sediment (intense shearing), while Site U1394 offshore Montserrat penetrated a flat-lying block of intact strata. The most likely mechanism for generating these large-scale seafloor sediment failures appears to be propagation of a decollement from proximal areas loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation. Under some conditions, volcanic island landslide deposits composed of mainly seafloor sediment will tend to form smaller magnitude tsunamis than equivalent volumes of subaerial block-rich mass flows rapidly entering water. Expedition 340 also successfully drilled sites to access the undisturbed record of eruption fallout layers intercalated with marine sediment which provide an outstanding high-resolution data set to analyze eruption and landslides cycles, improve understanding of magmatic evolution as well as offshore sedimentation processes. KW - landslide KW - volcanic island KW - debris avalanche KW - seafloor sediment failure KW - tsunami KW - IODP Y1 - 2015 U6 - https://doi.org/10.1002/2014GC005652 SN - 1525-2027 VL - 16 IS - 2 SP - 420 EP - 442 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Korup, Oliver A1 - Mohr, Christian Heinrich A1 - Manga, Michael M. T1 - Bayesian detection of streamflow response to earthquakes JF - Water resources research : an AGU journal N2 - Detecting whether and how river discharge responds to strong earthquake shaking can be time-consuming and prone to operator bias when checking hydrographs from hundreds of gauging stations. We use Bayesian piecewise regression models to show that up to a fifth of all gauging stations across Chile had their largest change in daily streamflow trend on the day of the M-w 8.8 Maule earthquake in 2010. These stations cluster distinctly in the near field though the number of detected streamflow changes varies with model complexity and length of time window considered. Credible seismic streamflow changes at several stations were the highest detectable in eight months, with an increased variance of discharge surpassing the variance of discharge following rainstorms. We conclude that Bayesian piecewise regression sheds new and unbiased insights on the duration, trend, and variance of streamflow response to strong earthquakes, and on how this response compares to that following rainstorms. KW - Bayesian analysis KW - Chile KW - discharge KW - earthquake KW - streamflow changes Y1 - 2021 U6 - https://doi.org/10.1029/2020WR028874 SN - 0043-1397 SN - 1944-7973 VL - 57 IS - 7 PB - Wiley CY - Hoboken, NJ ER -