Monday, 25 July 2011

INFOMAR marine geologist reports from the Mid-Atlantic Ridge

The VENTuRE Cruise, Research and Rescuing information from the deep with GSI based marine geologist Maria Judge onboard.
Location: 45°28.9'N 27°44.5'W Date: 20.07.11 Time: 18:00 hrs

The R.V. Celtic Explorer at Galway docks before sailing for the Mid-Atlantic Ridge.
Holland 1 the Marine Institute's remotely operated vehicle will be used to explore the Mid-Atlantic Ridge and enhance our current knowledge of vent and seep systems.


The scientists and crew of the Venture research survey, to 45°N on Mid-Atlantic Ridge and the Irish cold-water corals of the Moira Mounds, have been onboard the R.V. Celtic Explorer since July 11th . This joint venture is lead by Andy Wheeler from University College Cork (UCC) in conjunction with the Marine Institute (MI), National Oceanographic Centre Southampton (NOC) in the United Kingdom, Geological Survey of Ireland (GSI), National University of Ireland, Galway and National Geographic Television. Our venture began by readying our equipment, including the MI's deep-diving ROV "Holland 1" and preparing protocols to handle the huge amounts of data we expect to acquire.
Our mission is highly aspirational (and ambitious); we sail on the RV Celtic Explorer to 45°N, a portion of the Mid-Atlantic Ridge, in search of Deep Hydrothermal Vents (otherwise known as Black Smokers). We intend to use the Irish ROV Holland, a deep-water remotely operated vehicle, to survey this idiosyncratic environment and its unique chemosynthetic ecosystems. This mission follows an earlier survey carried out at 45°N by NOC in 2008 which studied an Axial Volcanic Ridge and serendipitously discovered water column signatures typical of high temperature hydrothermal venting. These sparse indications were of dark smoky water, some 2600m below the sparkling blue ocean and hovering above the young volcanic ridge.
Our plan for this expedition is to actually find the source of the venting on the deep sea floor, photographically document it, make high-resolution multibeam sonar images and collect rocks and animals from the site. After this, we plan to steam back toward the Moira mounds, cold-water coral mounds in the Porcupine Seabight, to survey, video and sample these beautiful and ecologically valuable habitats.
On the 15th of July, with everyone onboard, we sailed out of a tranquil Galway Bay towards the setting sun. We passed the Galway Bay esker islands, the Aran Islands and daunting Cliffs of Moher standing proud to port and the Galway's granitic coastline framed by the dominating Dalradian metamorphic mountains of Connemara to starboard. Our sunset departure was captured on film from a helicopter by National Geographic TV who is onboard filming a documentary on our deep sea exploration. There was an air of excited anticipation on board, and some anxiety, as we had been experiencing some technical problems that cost us precious time. We were also aware that we would soon be faced with a howling North-west gale conjuring 3 to 4 metre swells.
With the technical issues solved, the mobilisation, calibration and wet tests of the CTD, underwater navigation system, the ROV, and ROV-mounted multibeam echosounder commenced. Happy with the results we steamed ahead into increasingly worsening weather that would actually average a 7m swell. As the waves grew in height and the ship rolled wildly all night, and with concern for the vessel and its expensive cargo, Denis the Captain decided to keep the vessel faced into the wind and hove-to until conditions eased enough to continue the transit. With most of the scientific team seasick, morale was low and concern increased as precious time ticked by.
Meanwhile, some scientists began to feel better, and began the analysis of previously acquired data. It was crucial at this point to constrain a target location and plan the best course of action. We started by integrating data acquired during the NOC cruise in 2008, using programs such as the 3D visualisation software Fledermaus and 2D geographic information mapping software Arc Map, where various layers of information are draped in one virtual environment. This method of display shows the topography of the ocean floor, the magnetic and sidescan imagery of the ocean floor and varying temperature and chemical signatures of the water column all in one visual space. Using our knowledge and some intuitive guess work we compared each attribute to locate the most plausible position for hydrothermal venting.
The team gathered and discussed the merits of one particular 'hot-spot' of interest; result! As a target location for the first analysis was decided. We then established the best course for our survey: to perform Tow-Yo CTD casts over the area. CTD stands for Conductivity, Temperature and Depth, these are just some of the parameters measured by this hardware. It is to be deployed over the side of the ship and moved through a section of water close to the sea floor (~3000m) by towing it in a yo-yo style we can assess the chemical signatures of the water column at varying heights. This we hoped would indicate the source where the 'buoyant plume' or 'smoke' of minerals ejected from the hydrothermal vent is located.
With the weather improving and a plan of action formed we are confidently steaming toward the target location. By first light we could be on location commencing survey.

Screen grab showing data (e.g. magnetic, sidescan and bathymetry) used to target ROV dives at the Mid-Atlantic ridge using the Holland 1 ROV.



For more on the VENTuRE cruise, please check out the Science blog spot: http://scientistsatsea.blogspot.com
And UCC's student website: http://blogs.ucc.ie/wordpress/bees

Tuesday, 19 July 2011

The R.V Keary @ Waterford Tallships Festival 2011


The RV Keary, a 15m aluminium catamaran is a state-run marine research survey vessel built for and operated by the Geological Survey of Ireland (GSI). Its primary function is to provide an inshore survey capability for the national INFOMAR programme (INtegrated Mapping FOr the Sustainable Development of Ireland’s MArine Resource).

The RV Keary’s first INFOMAR survey leg of 2011 took place in Waterford Harbour, starting in mid-April and finishing in mid-June.

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for more information.

The campaign focused on mapping the navigational channel in advance of the Tall Ships Festival which took place at the end of June, with mapping of the shallower areas along the river banks and shore being carried out by the GSI's 7.5m RIB, RV Geo. This was the first time that both vessels have worked in tandem.

Having successfully mapped the estuary the RV Keary was invited to participate in the Tall Ships Festival. The RV Keary was positioned in Waterford Marina beside The Revenue Commissioners customs cutter, the RCC Faire. The Keary was open to the public from Thursday afternoon June 29th until Saturday evening on July 2nd.


Seabed mapping of the estuary took place in an area west of the city's Rice Bridge to the open sea at the mouth of Waterford Harbour. Photo of RV Keary at Waterford Tallships
Visitors to the Tall Ships event were invited onboard in groups of approximately 15, and those waiting for the tour were informed of the INFOMAR programme through the display of posters outlining the history of the RV Keary and the INFOMAR programme attached to the vessel’s hull.




The tour commenced on the back deck where a brief introduction to the RV Keary, the 'Real Map of Ireland', the GSI, Marine Institute (MI), INFOMAR project and the survey acquisition systems and instrumentation was provided. Visitors were also shown the mapping tools used onboard such as the side scan sonar, the magnetometer and the grab sample equipment on the back deck and invited to ask questions on any aspect of the INFOMAR programme.

Following this, the groups were presented with an overview of the data acquired during the Waterford Harbour survey on the data processing pc. Features of interest in the data were highlighted, in particular a 60m shipwreck discovered opposite the marina in Waterford city. This vessel is believed to be the cargo ship the S.S. Harvard, dating from 1870, now embedded in a scour feature in the river bank just a kilometre from where the R.V. Keary was berthed. Also of great interest was the detailed imagery of whirlpool scours (dark blue - purple), created where the river flow meets the tide.

3D image of shipwreck SS Harvard
imagery of whirpool scours (dark blue - purple), created when the river flow meets the tide in waterford estuary
Next the group was invited to view the 'pod' which is located in the middle of the vessel between the two hulls. The pod is designed to accommodate the geophysical equipment onboard such as the single beam head, multibeam heads, chirp, USBL transceiver and SV sensor in one housing. The pod is mounted on a hydraulic ram that can raise and lower the instrumentation into and out of the water. Once the pod has been lowered into the survey position, lateral rams lock the pod in place to ensure that the system is stable and the instrumentation is in the same position each time the pod is moved.

Finally, a tour of the bridge and its instrumentation was provided. The Navigation and Communication Equipment was explained including the POS MV (GPS technology) which logs all motion information in space and time, allowing the removal of the vessels motion from the sonar and shallow seismic datasets. Also, the forward looking sonar which provides information about the nature and depth of the seabed ahead of the Keary and the auto pilot steering of survey lines. A 3D fly-through of Waterford Harbour on display generated huge interest with visitors receiving a 3D visual of the seabed of Waterford harbour.
video
To the delight of the visitors onboard, RV Keary and Real Map of Ireland postcards were distributed along with copies of Inshore Ireland ( with Keary articles), and information on the copper coast geopark project and Marine Institute, not forgetting our younger visitors, the kiddies who received lollipops! The visitors were then free to explore the front deck of the vessel and take photographs.

Over 1,000 people came onboard to visit the RV Keary on guided tours over the three days and the positive feedback and interest in the INFOMAR programme and the data being acquired was exceptional.

On the final day of a highly successful Tall Ships event, the RV Keary participated in the 'Parade of Sails' on Sunday 3rd July. The parade was led by the naval vessel the L.E. Aoife, followed by the RCC Faire with the RV Keary in third position ahead of the biggest tallship the Russian owned 'Mir' and the remainder of the Tall Ships fleet.

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Le Aoife leads the parade of sails
Russian Tallship Mir following the RV Keary
Le Aoife and RCC Faire lead the Parade of Sails
Tallships in Waterford Marina
Colombian Tallship Gloria
Polish Tallship Polgoria