Synonyms for subseafloor or Related words with subseafloor
Examples of "subseafloor"
Beneath the seafloor, the marine sediments and surrounding porewaters contain an unusual
biosphere. Despite extremely low amounts of buried organic material, microbes live throughout the entire sediment column. Average cell abundances and net rates of respiration are a few orders of magnitude lower than any other
biosphere previously studied.
The prehnite-pumpellyite facies is a metamorphic facies typical of
alteration of the oceanic crust around mid-ocean ridge spreading centres.
The South Pacific Gyre
community is also unusual because it contains oxygen throughout the entire sediment column. In other
biospheres, microbial respiration will break down organic material and consume all the oxygen near the seafloor leaving the deeper portions of the sediment column anoxic. However, in the South Pacific Gyre the low levels of organic material, the low rates of respiration, and the thin sediments allow the porewater to be oxygenated throughout the entire sediment column.
The zeolite facies is generally considered to be transitional between diagenetic processes which turn sediments into sedimentary rocks, and prehnite-pumpellyite facies, which is a hallmark of
alteration of the oceanic crust around mid-ocean ridge spreading centres. The zeolite and prehnite-pumpellyite facies are considered "burial metamorphism" as the processes of orogenic regional metamorphism are not required.
Alternately, SedEx deposits may be sourced from magmatic fluids from
magma chambers and hydrothermal fluids generated by the heat of a magma chamber intruding into saturated sediments. This scenario is relevant to mid-ocean ridge environments and volcanic island arcs where black smokers are formed by discharging hydrothermal fluids.
The axial deep of the rift was the location of the first known hot hydrothermal brines discovered on the sea floor. Workers from 1949 through the 1960s confirmed the presence of hot () saline brines and associated metalliferous muds. The hot solutions were emanating from an active
In 1949, a deep water survey reported anomalously hot brines in the central portion of the Red Sea. Later work in the 1960s confirmed the presence of hot, 60 °C (140 °F), saline brines and associated metalliferous muds. The hot solutions were emanating from an active
rift. The highly saline character of the waters was not hospitable to living organisms. The brines and associated muds are currently under investigation as a source of mineable precious and base metals.
Spivack’s research interest is the geochemistry of the oceans, atmosphere, and crust. He developed the use of boron isotopes for determining the pH of ancient oceans. This approach provides a principal basis for estimating atmospheric CO2 concentrations of the last several tens of million years. He led the investigation of the 2015 Salty Brine Beach explosion. He has also contributed to scientific understanding of geochemical fluxes in mid-ocean-ridge hydrothermal systems and subduction zones and understanding of
The International Ocean Discovery Program (IODP) is an international marine research collaboration dedicated to advancing scientific understanding of the Earth through drilling, coring, and monitoring the
. The research enabled by IODP samples and data improves scientific understanding of changing climate and ocean conditions, the origins of ancient life, risks posed by geohazards, and the structure and processes of Earth’s tectonic plates and uppermost mantle. IODP began in 2013 and builds on the research of four previous scientific ocean drilling programs: Project Mohole, Deep Sea Drilling Project, Ocean Drilling Program, and Integrated Ocean Drilling Program. Together, these programs represent the longest running and most successful international Earth science collaboration.
The Red Sea was formed by the Arabian peninsula being split from the Horn of Africa by movement of the Red Sea Rift. This split started in the Eocene and accelerated during the Oligocene. The sea is still widening, and it is considered that it will become an ocean in time (as proposed in the model of John Tuzo Wilson). In 1949, a deep water survey reported anomalously hot brines in the central portion of the Red Sea. Later work in the 1960s confirmed the presence of hot, 60 °C (140 °F), saline brines and associated metalliferous muds. The hot solutions were emanating from an active
rift. The high salinity of the waters was not hospitable to living organisms.
IODP uses multiple drilling platforms ("JOIDES Resolution", "Chikyu", and mission-specific platforms) to access different
environments during research expeditions. These facilities are funded by the U.S. National Science Foundation (NSF), Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT), and the European Consortium for Ocean Research Drilling (ECORD), alongside the Ministry of Science and Technology of the People's Republic of China (MOST), Korea Institute of Geoscience and Mineral Resources (KIGAM), Australian-New Zealand IODP Consortium (ANZIC), India Ministry of Earth Science (MoES), and Brazil’s Coordination for Improvement of Higher Education Personnel (CAPES). Together, these entities represent a coalition of 26 countries. The IODP funding model differs from the Integrated Ocean Drilling Program in that NSF, MEXT, and ECORD each manage their own drilling platform. International partners directly contribute to the operating costs of the drilling platforms in exchange for scientific participation on the expeditions and seats on the advisory panels.
In some locations along Russia’s northern coast, methane rising from the sea floor to the surface has caused the sea to foam. However, most methane chimneys do not produce such visible signs at the sea surface. Instead, plumes are identified by a combination of chemical and physical oceanographic and geologic data. Plumes of methane bubbles, whether in the water column or
sediments, have lower density and sound speed than the surrounding water. As such, these plumes can be imaged by a variety of acoustic techniques, including seismic reflection data and conventional fishfinders. Dissolved methane is usually identified through widespread chemical analysis of water samples, including gas chromatography of gasses extracted from the headspace of seawater samples taken at depth (headspace is the space above a sample in a sealed container, which forms as higher temperature and lower pressure allows gasses to come out of solution). Continuous measurements of methane concentration in seawater can be made by underway ships using cavity ring-down spectroscopy.
Copyright © 2017