Much was heard from the southern hemisphere this week. Sunday morning (our time) was punctuated by a magnitude 7.8 earthquake in New Zealand on the complex plate boundary that links the subduction zone along the Hikurangi Trough east of North Island to the transform fault through South Island.
Kirsty Tinto reported Sunday on the progress of Lamont’s IcePod group now in Antarctica to conduct the next phase of the Rosetta project to survey the Ross Ice Shelf. Kirsty wrote, “We have now been in McMurdo for one week and have set up our ground-based operations in anticipation of flights when aircraft are available. The team has assembled, and we have representatives from all project partners: Kirsty Tinto, Nick Frearson, Chris Bertinato, Alex Boghosian, Isabel Cordero, Tej Dhakal, Dave Porter, and Sarah Starke from Lamont, Alec Lockett from Colorado College, Scott Springer from Earth and Space Research, Maya Becker from Scripps Institution of Oceanography, Beth Burton from the U.S. Geological Survey, and Fabio Caratori Tontini and Grant O’Brien from GNS Science in New Zealand…We have been checking out the hardware that will be installed on the plane. The gravity pallet has been built, with two rack-mounted gravimeters that were flown last year as well as a new iMAR IMU (inertial measurement unit) that is being operated as a strap-down gravimeter. So far, so good, as all systems are operating well. This year we also plan to deploy ALAMO ocean floats to measure temperature and salinity of the water masses in front of the ice shelf. We are working with the Air National Guard to get the necessary approvals for this work, and good progress is being made…There is a substantial backlog of flights program-wide, so we did not install the IcePod on Friday night, but we’re hopeful that we can get underway next week.”
Margie Turrin continued her blog this week from the IceBridge team, also in Antarctica (http://www.ldeo.columbia.edu/research/blogs/tracking-antarcticas-ice-shelves). Her post Monday was on the break-up and disappearance of the Larsen ice shelves at the western edge of the Weddell Sea. Not to be outdone is the R/V Langseth, from which chief scientist Anne Tréhu from Oregon State University and her fellow scientists on the PICTURES (Pisagua/Iquique Crustal Tomography to Understand the Region of the Earthquake Source) expedition off Chile maintain a blog as well (http://blogs.oregonstate.edu/pictures/).
Arnold Gordon was quoted in a news story on Wednesday in Nature magazine on the complex role of the Southern Ocean in absorbing carbon dioxide and heat from the atmosphere (https://www.scientificamerican.com/article/antarctica-rsquo-s-southern-ocean-may-no-longer-help-delay-global-warming/).
Equatorial regions, too, received attention this week. Nature posted online a paper by Yen Joe Tan, Maya Tolstoy, Felix Waldhauser, and the University of Washington’s William Wilcock reporting a new analysis of the seismic events associated with a 2006 seafloor eruption along the East Pacific Rise at 9°50’N. On the basis of earthquakes located with a hydroacoustic monitoring network and the remnants of an ocean-bottom seismometer network that only partially survived the eruption, as well as seismic events identified as signatures of magma ascent and the interaction of freshly erupted lava with seawater, the group deduced that the eruption episode was concentrated within a two-day interval and had been preceded by earthquakes along a 35-km length of the rise axis. They suggested that tectonic movement of the seafloor along multiple ridge segments, rather than changes in magma pressure, triggered the eruption. A Kevin Krajick press release appears on the Lamont web site (http://www.ldeo.columbia.edu/news-events/rip-crust-drives-undersea-volcanism-study-says).
Also in the equatorial Pacific is the R/V Atlantis, from which Bridgit Boulahanis started a blog this week (http://www.ldeo.columbia.edu/research/blogs/cruising-oasis). Bridgit is part of an expedition surveying a seamount chain near the East Pacific Rise and the Siqueiros Fracture Zone with multibeam bathymetry, an autonomous underwater vehicle, and the research submersible Alvin.
On Tuesday, Science of the Total Environment posted online a paper by Beizhan Yan, Martin Stute, James Ross, Steve Chillrud, and colleagues from the Mailman School, Barnard College, Rutgers University, and the University of Pennsylvania reporting analyses of groundwater samples near unconventional gas wells in northeastern Pennsylvania that were produced by hydraulic fracturing conducted in the area since 2007. The group divided their samples by proximity to a gas well (less than or greater than 1 km distance) and elevation (“valley” versus “upland”), and they found larger concentrations of major dissolved constituents near a well and in valley settings at a given distance range. Their results are consistent with mixing of shallow and deep groundwater stimulated by the procedures used to develop the gas wells, but the authors emphasized that more work is needed to document effects of unconventional gas development on water quality and human health. A Kevin Krajick story on the paper’s findings is on our web site (http://www.ldeo.columbia.edu/news-events/study-links-groundwater-changes-fracking).
Added to our web pages Wednesday was a Kevin Krajick photo essay and video on this summer’s fieldwork by Natalie Boelman, Kevin Griffin, Johanna Jensen, and colleagues in the vicinity of the northern tree line of Alaska (http://www.ldeo.columbia.edu/news-events/where-trees-meet-tundra-decoding-signals-climate-change). Their work on the response of the region to recent climate change is part of the NASA-sponsored Arctic Boreal Vulnerability Experiment (ABoVE).
Terry Plank received prominent mention in a news feature in today’s issue of Science on the ability of geochemists and volcanologists to read, from the trace element chemistry of crystals in volcanic deposits, information on the timescales for cooling and ascent of subsurface magmas (http://www.sciencemag.org/news/2016/11/smudged-volcanic-crystals-offer-clues-past-eruptions).
On Monday next week, Lamont will host a workshop on “Developing international collaboration and cooperation for marine seismics and increasing opportunities for scientific ocean drilling.” The workshop has been organized through the International Ocean Discovery Program’s U.S. Science Support Office and the Marcus Langseth Science Oversight Committee and will be chaired by Jamie Austin of the University of Texas, Austin. Lamont participants will include Anne Bécel, Suzanne Carbotte, Dave Goldberg, Sean Higgins, Art Lerner-Lam, and Donna Shillington.
This afternoon, the Earth Science Colloquium will be given by carbonate chemist and sedimentologist Andrea Dutton, an Assistant Professor in the Department of Geological Sciences at the University of Florida (https://sites.google.com/site/ufadutton/home). Andrea will be speaking on “Polar ice sheet retreat during past warm periods: An update from the Seychelles.” I hope to see you there.