Transcript AT24-05_Precis_130503x - University of California, Santa Cruz

AT25-04: Hydrogeologic, Geochemical, and
Microbiological Experiments in Young Oceanic
Crust of the Northeastern Pacific Ocean Using
Subseafloor Observatories
S. Cooper1, A. T. Fisher2, and NSF co-PIs3
1
Consortium for Ocean Leadership
2 Earth and Planetary Sciences Department and
Center for Dark Energy Biosphere Investigations
University of California, Santa Cruz
3 K. Becker, J. Clark, J. Cowen, C. G. Wheat
OET Nautilus Workshop
University of Rhode Island, ISC
6–9 May 2013
Most of the seafloor is hydrogeologically active…
modified from Ge et al. (2003); Fisher (2005)
Seafloor hydrogeology influences...
…the physical state and evolution of the crust and mantle,
including volatile cycling at subduction zones;
…the chemical evolution of the oceans;
…heat loss and the thermal evolution of Earth; and
…development and evolution of remarkable biological
communities, both on and within the crust.
Focus of this expedition:
seafloor hydrothermal circulation
The upper
oceanic crust
is a globalscale aquifer
A permeable
aquifer…
Overview of CORK subseafloor observatories
Created by Stephanie Keske, IODP Expedition 327
Department of Visualization, Texas A & M University
Post-drilling CORK servicing with ROV
Hydrogeology, Geochemistry, Microbiology
Following IODP Expedition 327, CORK servicing accomplishing by
ROV in Summer 2011 (very successful!)
• Deploy long-term well-head OsmoSampling systems to collect
fluids, run microbiology incubation experiments
• Extract, collect, filter, analyze samples from well-heads using
active pumping systems
• Deploy flowmeter and open large-diameter valve to allow
measured free-flow of hydrothermal fluids, create pressure
perturbation, collect samples
• Expedition AT25-04 (Summer 2013) is designed to "wrap up" initial
phase of single-hole and multi-hole experiments through
sampling, data downloads, perturbation of experimental systems
CORK Observatory System in Operation!
Planning for 2013 (AT25-04) and beyond…
Download pressure data
ROV Jason
Exchange flowmeter
Exchange
OsmoSamplers
Recover GeoM sled
Large EOC effort planned (5-6 participants)
Summer 2013
Education, Outreach, Communication
IODP 327, AT18-07, AT25-04
pore
Orcutt et al. (2011)
• Numerous web conferences
(schools, museums)
• EOC and scientist blogs
• Adopt-a-Microbe program
• Podcasts, videos, photography
• Curriculum development,
museum displays
• High-band-width "telepresence" with OET/URI!
Acknowledgements
Collaborators:
Collaborators from ODP Leg 168, IODP Expeditions 301 and
327, numerous R/V Atlantis expeditions during 2004-11+…
Funding, leadership:
Thank you!
Ship operators, crew,
techs:
Seafloor hydrothermal circulation is…
…the passage of warm (or hot) water through rock of the
oceanic crust;
…generally a result of heating from below, although it can also
occur immediately adjacent to newly-erupted magma;
…partly responsible for making the ocean "salty";
…thought likely to have occurred very early in Earth history and may occur on other planetary bodies in our solar system.
This presentation explores large-scale,
ridge-flank hydrothermal systems
(in contrast to "black smokers")
Ridge-flank hydrothermal systems are
subtle but important…
…far from the magmatic and thermal influence of seafloor
spreading;
…fluid temperatures are often ~5-30°C, so systems are hard to
detect;
…driving force is heat rising slowly from deep inside the Earth, not
active volcanism;
…result in huge fluid flows, chemical impacts less well understood;
…may help to support vast, subseafloor ecosystems (thermal and
other conditions are optimal).
Eastern Flank of the Juan de Fuca Ridge
Hydrogeology, Geochemistry, Microbiology
Focus on active ridge-flank processes to address these questions:
• What are the magnitude and nature (distribution, extent of channeling) of
permeability in crustal fluid-rock systems, variations, scaling (temporal, spatial)?
• What are the magnitudes and directions of driving forces, fluid fluxes, and
associated solute, heat , and microbial transport?
• What are the magnitude and nature of storage properties, variations with fluid
pressure, scaling (temporal, spatial)?
• What are relations between fluid flow, vertical and horizontal
compartmentalization, microbiological communities, seismic properties,
alteration, structure, and primary crustal lithology?
• How large are distinct fluid reservoirs, what are fluid residence times and fluid
velocities, and how do these respond to transient events and processes (tides,
seismic events)?
Center for Dark Energy Biosphere Investigations (C-DEBI)
Site Primary
Review, 2013:
Juan de Fuca Ridge Flank
fieldFisher,
locations
modified from Fisher, Tsuji et al. (2011)
New borehole observatories installed in 2010
IODP Expedition 327: Site 1362
Instrument and
sampling bays
Center for Dark Energy Biosphere Investigations (C-DEBI)
Microbiologist
for scale
Site Review, 2013: Fisher, Juan de Fuca Ridge
Flank
First controlled measurement of
water, solute particle velocity!
Started Summer 2010
IODP Exp. 327
modified from Fisher et al. (2011)