MR1 Archive:2001 Cruises | DRIFT04(RR0101)

General Info

DRIFT Leg 4 R/V Revelle  Scientific Personnel List

Dr. Mark Kurz – Chief Scientist
WHOI, Marine Chemistry & Geochemistry Dept.

Dr. Dan Fornari – Co-Chief Scientist
WHOI, Geology & Geophysics Dept.

Prof. Denny Geist – Co-Chief Scientist
University of Idaho, Dept. of Geology

Mr. JJ Becker – data analyst
Scripps Institution of Oceanography/GRD GDC

Ms. Kate Buckman – student
Sea Education Association (SEA) and WHOI

Mr. Francisco Cruz – observer
Charles Darwin Research Station

Mr. Josh Curtice – technician
WHOI

Ms. Jenny Engels – graduate stuent.
University of Hawaii, SOEST

Mr. Todd Ericksen – technician
University of Hawai’i, Hawaii Mapping Research Group

Mr. Ben Grosser – grad student
University of Idaho

Mr. Jeremey Haney – undergraduate student
University of Idaho

Prof. Karen Harpp
Colgate University

Mr. Dan Jacobson – computer technician
SIO

Mr. Paul Johnson – MR1 Expedition Leader
University of Hawai’i, Hawaii Mapping Research Group

Dr. Joe Licciardi – Post-Doc.
WHOI

Mr. Robert Otto – undergraduate student
Colgate University

Mr. Jules Paredes-Jarrin – observer
Galapagos National Park

Ms. Uta Peckman – data analyst
SIO – Geologic Data Center

Mr. Gene Pillard – resident technician
SIO

Ms. Christina Reed – science writer
WHOI

Dr. Bob Reynolds
Central Oregon Community College

Dr. Alberto Saal
Lamont Doherthy Earth Observatory

Mr. Steve Tottori – technician
University of Hawaii SOEST/HMRG

Mr. Steve Volpe – undergraduate student
University of Florida

Ms. Rhian Waller – graduate student
Southampton Oceanography Centre, UK

Track Charts

Regional Track Chart

Survey Track Chart

Chronology

Chronology (all times Z = GMT)

8/21/01

Depart Puntarenas ~1200L (+6 for entire cruise). In transit at 12knots towards the Galápagos

8/24/01

Transiting at 12 knots. Passed Cocos Island ~1200L.

8/25/01

Started multibeam survey at 2248Z, DRFT04 – 01-NE rift zone of Genovesa Island

8/26/01

Deployed MR1 at 0210Z for compass calibration and flat-bottom survey
MR1 fish recovered by 1445Z
Multibeam off (too shallow)
Transit to Puerto Ayora, arrived at 2100Z

8/27/01

Left Puerto Ayora at 2200Z
Multibeam turned on at 2300Z to survey NNE of the Wittmer Seamount

8/28/01

MR1 deployed at 0320Z, starting Survey 1 to the S of Wittmer Smt.  Survey lines spaced to allow for overlap of multibeam data as well as MR1 imagery.  Lines are oriented generally NE-SE.

8/29/2001  

Continued MR1 survey – completed Survey 1 at 2012Z, started Survey 2
tow-fish recovered at 2320Zdue to loose hardware.

8/30/2001

MR1 redeployed by 0015Z for Survey 2
Passing over platform between Isabela and Fernandina

8/31/2001  

Passing the SE edge of Roca Redonda, approaching Wolf volcano

9/1/2001

MR1 recovered by 0857Z, transiting to first dredge site
Completed dredges 1 and 2, S of Roca Redonda
Start dredge 3 SE of Roca Redonda

9/2/2001  

Dredges 3 – 7 completed,  moving around Volcan Ecuador
Begin dredge 8 – SE of Volcan Ecuador

9/3/2001

Dredges 8 – 11 complete
Simrad survey to N coast of Fernandina between 1904Z and 2115Z
Dredge 12 complete – N of Fernandina

9/4/2001

Dredges 13 – 15 complete
1336Z start mulitbeam survey to the N Fernandina, close to the island
Dredges 16 and 17 complete

9/5/2001

Dredges 18 – 21 complete, around Fernandina

9/6/2001

Camera Tow 1 on flow WNW of Fernandina between 0011Z and 0845Z
Tensiometer repairs required so moved on the rock coring W of Fernandina
Rock corer deployed – RC01 – RC04 complete

9/7/2001  

RC05 complete – W of Fernandina
0815Z MR1 deployed for Survey 3, to NE rift zone of Genovesa, survey went between Marchena and Pinta Islands

9/8/01

MR1 recovered by 0540Z
Dredges 22-23 complete, ridge Genovesa
RC06 complete – End of Genovesa NE rift zone work, steam back to Fernandina with only multibeam sonar collecting data

9/9/01  

Dredge 24 complete – N Fernandina
1434Z WHOI deep-tow camera deployed for Survey 2 – NW rift of Fernandina
1648z camera stuck on bottom, wire broke, lost camera
2103Z broken end of wire on deck

9/10/01

Dredge 25 – 28 complete, SW of Fernandina

9/11/01

Dredge 29 – 33 complete, terraces S of Fernandina

9/12/01

Dredge 34 – 36 complete, terraces S of Fernandina
1904Z Multibeam survey – inshore area between Fernandina and Cerro Azul

9/13/01

Dredge 37 complete, terrace N of Cerro Azul
RC07 complete, cone N of Cerro Azul
Dredge 38 – 40 complete, N of Cerro Azul

9/14/01

Dredge 41 – 44 complete, SW rift of Cerro Azul

9/15/01  

Dredge 46 – 48 complete, S of Cerro Azul
1522Z Gravity core W of Cerro Azul
Dredge 49 complete, SE of Cerro Azul

9/16/01  

Dredge 50 – 54 complete, terraces S of Cerro Azul

9/17/01

Dredge 55 – 59 complete, S Isabela
1708Z Grab Sample 1 S of Isabela (no recovery)
Dredge 60 complete, S of Isabela

9/18/01

Dredge 61 – 64 complete, SE of Isabela
2020Z Multibeam survey while in transit to Floreana

9/19/01

Dredge 65 – 69 complete, Floreana ridge and SW of Floreana

9/20/01  

Dredge 70 – 73 complete, around Floreana and on terraces between Floreana and Isabela
1753Z Multibeam on during transit to Puerto Ayora at 12knots to drop off observers

9/21/01

Depart Puerto Ayora, Santa Cruz Isl. Galápagos for Puerto Caldera, Costa Rica – transiting at 12 knots.

9/22/01

Transiting to Costa Rica – Equator Crossing Ceremonies

9/23/01

Transiting to Costa Rica at ~12 knots

9/24/01

Arrival at Puerto Caldera, Costa Rica

Ops

Dredge log | Biology Samples | Biology Specimens

DRIFT Leg 04 | MR1 Operations Report |Hawaii Mapping Research Group

Mobilization

            The R/V Roger Revelle arrived in Puerto Caldera, Costa Rica on the morning of August 18.   The MR1 System was on the pier prior to the ship’s arrival and was immediately loaded onto Revelle by ship’s crew.  The ship then transited to immediately Puntarenas where the HMRG team arrived that afternoon.

Mobilization efforts continued on the follow morning, August 19.  The MR1 Launch and Recovery System, deck winch, and hydraulic power pack were positioned on the deck and the topside telemetry, acquisition, and processing computers set up in the ship’s hydrolab.  All preparations for survey were complete by the time the Revelle departed Puntarenas at noon on August 23.

Survey

            The MR1 was deployed three times in the course of DRIFT Leg IV.

A preliminary survey was planned to image the area northeast of Genovesa Island before stopping in Puerto Ayora, Galapagos.  MR1 was deployed August 26 north of Genovesa in a region of relatively flat seafloor.  Shortly after deployment a calibration of the towfish compass was performed by executing a complete 360° turn to port followed by a 360° turn to starboard.   Data collected from ships navigation and compass in the MR1 towfish were used to form a compass correction applied in the navigation of all MR1data.   Initial acoustic phase angle to nadir angle tables were produced from data collected over the flat seafloor.  The survey continued on from Genovesa toward Santa Cruz and ended just offshore of  Puerto Ayora.

The primary focus of the survey began within hours of leaving Puerto Ayora on August 28.  Over the next five days the areas to the south and southwest of Isabella and Fernandina islands and northwest of Isabella were imaged.

At approximately 2200 GMT on August 29 a significant amount of noise was seen in the MR1 realtime display and the decision made to recover the towfish.  The source of noise was quickly diagnosed as loose fasteners in the panels covering the electronics compartment.  The fasteners were tightened and sealed and the towfish redeployed.  The problem was fixed and surveying resumed within two hours of noticing the noise.  The survey  was completed without further event.

A third survey segment was performed on September 7th and 8th due to halted dredging operations.   The MR1 was deployed north of Isabella and  surveyed east between the islands of Pinta and Marchena and on to survey the ridge northeast of Genovesa.  The MR1 was recovered for the last time on September 8th.

            Preparations for demobilization began September 17 while continuing dredging operations.

Survey Timeline:

Segment Event Day/UTC
Depart Puntarenas, Costa Rica 235/1200
Tow01.01

GenovesaDrogue away

Deploy MR1

Begin calibration

Calibration complete

Recover MR1238/0220

238/0242

238/0340

238/0556

238/1445   Tow02.01

Fernandina – Isabella – FlorianaDrogue away

Deploy MR1

MR1 on deck – noise issues

Continue survey

Recover MR1240/0221

240/0340

241/2322

242/0036

244/0857   Tow03.01

Isabella – GenovesaDrogue away

Deploy MR1

Recover MR1250/0707

250/0727

251/0715

 

MR1 Settings

Ping Rate:             The HAWAII MR1 was operated using an external trigger to synchronize the transmit cycle with the R/V Roger Revelle’s EM120 multibeam sonar.  Attempts were made to optimize EM120 cycle to allow greatest possible sidescan return.

Pulse Width:            Pulse width was adjusted based on water depth and EM120 cycle according to the following table:

 

Pulse Width Water Depth EM120 cycle

2ms

< 1000m

6 – 10s

5ms

1000m – 3000m

10 – 12s

10ms

> 3000m

15 – 20s

Power:             Full, for the duration of the survey

Data Collection

            Raw data were recorded in hour files by the acquisition computer and logged to 8mm Exabyte tapes on a 24 hour basis.   Post-processing of acoustic imagery data was done on an ongoing basis throughout the survey and merged with navigation data collected from shipboard GPS.   Bathymetry data collected by MR1 was not used in this survey.

            HMRG produced final charts of the survey area at various scales, and with both the acoustic imagery data and the EM120 bathymetry data.   Data from the 1991 PLUME 2 and the 2000 AHA NEMO 2 cruises were also included in the bathymetry chart sets.   A summary of charts produced is included below.

Data Products Delivered

            All raw data recorded from the MR1 system exists on duplicate sets of 8mm Exabyte tapes labeled 11614 thru 11620 (red copy and blue copy), which will be kept in the HMRG data archive.

            Processed data was delivered in digital form in both RTL and postscript formats on compact disc.  Hardcopies of all charts were produced as page size plots and as A0 size plots.  Also delivered was a web browser based collection of PDF images of the complete chart set.

Summary of Charts Produced

Scale

Description

Number

1:400,000 Regional bathymetry

1

Regional acoustic imagery

1

1:200,000 Bathymetry

4

33m acoustic imagery

4

Bathymetry with dredge locations

4

33m acoustic imagery with dredge locations

4

1:100,000 Bathymetry

8

16m acoustic imagery

8

Bathymetry with dredge locations

8

16m acoustic imagery with dredge locations

8

1:50,000 Bathymetry

29

8m acoustic imagery

29

Bathymetry with dredge locations

29

8m acoustic imagery with dredge locations

29

Total number of charts in set:

1

Charts

1 to 050000


1 to 100000


1 to 200000


1 to 400000