AT42-12: Orcutt "Slow Life"

Ship

Vehicles

Cruise Party

Departure: May 15, 2019

Arrival: May 28, 2019

Operations Area

Science Objectives

This expedition is supported through one primary U.S. National Science Foundation award (OCE-1737017, “Microbial activity in the crustal deep biosphere”) to the Chief Scientist. In addition, complimentary research is being funded by one complimentary NSF award (OIA-1826734) to the Chief Scientist and three other investigators at the Chief Scientist’s institution (Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA); companion (pending) awards to collaborators at the University of Hawaii (Michael Rappé, OCE-1851582), Hawaii Pacific University (Olivia Nigro, OCE-1851045), and Hartwick College (Stephanie Carr, OCE-1851099); and a (pending) NASA award to the Chief Scientist (18-EXO18-0048). These awards support multidisciplinary sampling and experiments at subseafloor borehole observatories in oceanic crust on the eastern flank of the Juan de Fuca Ridge to assess microbiological processes in the deep biosphere. These experiments are intended to answer questions about how microscopic life survives under energy limitation in this subsurface habitat, to determine rates of biomass production and chemical cycling, to assess the interactions of viruses with hosts, and to conduct guided cultivation efforts.

The primary work area is on the eastern flank of the Juan de Fuca Ridge (Table 1, Figure 1). Six long-term borehole observatories (CORKs) in a 2.5 square kilometer area are separated by distances of 40 to 2460 m, five aligned along a northeast trend (Holes 1026B, U1301A, U1301B, U1362A, and U1362B) and one located 2.2 km to the east (Hole 1027C; Figures 2, 3). All of these holes were drilled, cased, cored, and tested, then instrumented with CORKs using the drillship JOIDES Resolution. These instrumented sites allow continuous monitoring of pressure and temperature at depth, sampling of fluids and microbiological material, and measurement of fluid flow rate using autonomous instrumentation (Figure 4). Most of these CORK systems require servicing with a submersible or ROV to download pressure data, recover samples, manipulate valves, and replace a variety of experimental systems (Figure 4). This is the primary operational goal of this scientific research, which will use the ROV Jason from the R/V Atlantis (operated by the Woods Hole Oceanographic Institution, Table 2).

Secondary objectives may include (if time permits, Table 1): servicing additional CORK systems located nearby the main work site, and/or mapping/sampling at nearby Baby Bare, Grizzly Bare, Mama Bare, Wuzza Bare, or Zona Bare outcrops (within 50 nmi of primary work site).

Science Activities

Specifically, we aim to accomplish the following objectives (Table 2), in order of priority:

-       Deploy custom incubation devices on the top of the Hole U1362B CORK to examine microbial growth rates and active community members in situ.

-       Collect small volume (~200ml each) crustal fluid samples from the tops of Holes U1362A and U1362B CORKs with custom “squeezer” syringes to examine fluid chemistry and microbial diversity.

-       Collect large volume (10s of liters) crustal fluid samples (and filters after in situ filtration) from multiple depth horizons of Holes U1362A and U1362S CORK through use of the mobile pumping system (MPS) coupled to Medium Volume Bag Samplers (MVBS) and Large Volume Bag Samplers (LVBS) for microbial cultivation, various ‘omics analyses, and viral analysis.

-       Filter large volumes of crustal fluids from Holes U1362A/B for viral particle concentration through standalone filtration units deployed on the CORK wellheads and tapping into discrete horizons via umbilicals.

-       Recover and deploy “OsmoSamplers” on the Hole U1362A/B wellheads for temporal tracking of chemical conditions in subsurface crust.

-       Attempt to quantify in situ gas (methane) concentrations with in situ sensors and gas-tight fluid collection.

-       Download pressure data from Holes U1362A/B.

-       Leave Holes U1301A, U1362A, and U1362B sealed with top plugs.

-       Measure temperatures of crustal fluids.

-       Deploy a flow meter on Hole U1362A.

-       Conduct full ocean depth CTD Niskin Rosette casts to examine microbial activity and diversity in the dark ocean water column.

-       If time permits (unlikely), conduct exploratory dives at nearby outcrops to find sites of diffuse venting for sampling and characterization.

-       If weather or mechanical issues arise that preclude ROV dives, we will collect multi-beam bathymetric data.

Additional Info

Stations:

Supporting documentation:

Shipboard Equipment

Shipboard Communication

CTD/Water Sampling

Critical CTD Sensors

Sample Storage

Navigation

Navigation

Winches

Wire use and application

Standard Oceanographic Cables

Portable Vans

Specialized Deck Equipment

Over the Side Equipment

Special Requirements

Additional Cruise Items/Activities

Hazardous Material

Radioactive Material

Additional Information

Site Survey

Navigation

Elevators

Science Supplied Equipment

Hazardous Material

Additional Information

Checklist

Checklist