BBLA redesign w/ controsThe Benthic Boundary Layer Array: A Modular, Reconfigurable Seafloor Observatory NodeN. Farr, C. Pontbriand, J. Ware, J. Kapit and R. Camilli

The Benthic Boundary Layer Array: A Modular, Reconfigurable Seafloor Observatory NodeN. Farr, C. Pontbriand, J. Ware, J. Kapit and R. Camilli

GULF OF MEXICO HYDRATES RESEARCH CONSORTIUM ANNUAL MEETING Oct. 26-27, 2010

GULF OF MEXICO HYDRATES RESEARCH CONSORTIUM ANNUAL MEETING Oct. 26-27, 2010

Re-deployment operations Sept 2010

Engineering work completed• Integrated Contros methane sensor

(power requirement 20W!!)• Recalibrated full suite of sensors• Reconfigured for

– multiple power systems, – asynchronous duty cycle,– independent data logging

Deployment completed• Deployed September 2010 in SW

crater area• Anticipated operational endurance

6-9 months• Data will be compared with 2009

deployment to:– investigate SW crater hydrocarbon

expulsion activity – Monitor for overprinting of

hydrocarbons from DWH spill

Benthic turbine a low water velocity electric generator for continuous recharging of the BBLA

Operational requirements• High efficiency enabling power generation in low

velocity (<0.2 m/s) currents• Light in-air weight to facilitate deployment, near-

neutral in water to minimize flotation requirement• Modular design, enabling compact storage on ships

pre/post deployment • Safely operate in currents up to 0.5 m/s

Calculated benthic water column velocity distribution at MC118

(based on nearby MMS data)

Results from trials • Tested in well on

WHOI dock

• Begins rotating in 5 cm/s currents

• Produces ~1 W of power in <0.5 m/s currents

• ~10 ft dia, 6 ft high and 200 lb in air

• Components pack flat and turbine is easy to assemble

CORK Optical Telemetry System

Wireless data transfer from seafloor instrument to surface vessel

Increase power to the CORK for higher bandwidth operation

Sensitive hemispherical receiver

• 2-inch PMT• Wide field of view gathers out-

of-plane light.• AGC with blanking circuit• Dynamic range Ws to 100s-nW

Optical Technology

High power hemispherical transmitter

• 24 commercial LEDs• 6 W avg. optical power

7

Lowered system mounted on light bar (blue)

CORK system on basket (green)

8

9

CTD mounted OTS

USBL transponder

SDSL modem for CTD cable transmission

Transects with lowered unit

Range (meters) Data transfer rate (mbps)

108 1, 5, 10

118 1,5

128 1,5

138 1

Measured power-vs-range