Exploration of submarine hydrothermal vents and associated mineralizations and geobio-systems
EXPLOSEA -1 Antarctic Expedition Daily Log
16/2/2018 to 11/3/2018
Written by Filipa Marques aboard research vessel Hesperides during the Explosea Cruise
Explosea research group and Hesperides crew arriving to Ushuaia (Argentina)
8 March 2019 Happy International Woman´s Day aboard R/V Hespérides in Antarctica
Monday, 4 March 2019
We are approaching the final days of the cruise and so it is important to initiate the process of compiling all acquired data, e.g. sample lists, methodologies, observations, logs, preliminary results, etc. All scientists will be therefore involved in the making of a Cruise Report. Today most of us were involved in this task. The ship has been all day doing seismics along the Bransfield straight near the Three Sisters submarine volcanoes. Later we will start with CTD profiles and gravity cores in the Three Sisters area.
Sunday, 3 March 2019
After a night of sparker seismic with very good data we have spent the morning and early afternoon at Fumaroles bay retrieving more seawater near the bubbling vents and at shallow depths. The EMEPC team also proceeded with HD filming of the sea bottom and sediment sampling with a mini-dredge. In the afternoon a second team went to a marker CR70 south of the Hidden Lake. The purpose was to investigate historical records of fumarolic activity in the area. None was observed however the pebbles at the beach were covered by an orange patine. South of this area, on Pendulum Cove where the Chilean base was once, we have sampled warm (~24ºC) waters with no evidence of S release. Several CTDs and gravity corers were done while the teams were on-land studying the fumarolic activity. During the night the ship will continue with sparker seismics within the caldera.
Saturday, 2 March 2019
After a night of sparker seismic with very good data we have spent the morning and early afternoon at Fumaroles bay retrieving more seawater near the bubbling vents and at shallow depths. The EMEPC team also proceeded with HD filming of the sea bottom and sediment sampling with a mini-dredge. In the afternoon a second team went to a marker CR70 south of the Hidden Lake. The purpose was to investigate historical records of fumarolic activity in the area. None was observed however the pebbles at the beach were covered by an orange patine. South of this area, on Pendulum Cove where the Chilean base was once, we have sampled warm (~24ºC) waters with no evidence of S release. Several CTDs and gravity corers were done while the teams were on-land studying the fumarolic activity. During the night the ship will continue with sparker seismics within the caldera.
Friday, 1 March 2019
Full work day at Fumarolas bay, Deception Island. The team was divided in several groups to fill in 3 work shifts on the island. The first group headed to the Island in early morning during low tide to sample inter-tidal fumaroles. From the Zodiac the EMEPC team followed a sampling grid and proceeded with exhaustive CTD profile analysis and water sampling of the submarine fumaroles. On-land, fluid geochemists (Maria Asensio and Cecilia Amonte, on the lower left) from the INVOLCAN sampled gas from the strongly steaming fumarole 1. We have recovered a large amount of samples that are now being processed and stored for further analysis. Javier Gonzalez (on the lower right) from IGME sampled sediments, precipitates and rock samples with material associated to the fumarolic activity. Fluid geochemists sampled gas from the strongly steaming fumarole 1. We have recovered a large amount of samples that are now being processed and stored for further analysis. During the night we will proceed with seismic and CTD profiles (this time from the ship). Tomorrow we will follow up with the exploration of shallow hydrothermal exploration
Thursday, 28 February 2019
Another wonderful sunny day with calm seas. The Buque Hespérides continued its high resolution bathymetry data acquisition later coupled with seismic west of Deception island. The EXPLOSEA team used the spare time to prepare for the work ahead in the Deception island caldera. We had to prepare push corers, CTDs, vials, and schedule the teams in order to assure the best use of time possible. All is set now and we expect great work days ahead.
Wednesday, 27 February 2019
The Buque Hespérides covered in detail the Axe volcano seafloor using high resolution multi-beam bathymetry and TOPAS. We have mapped with high resolution very interesting neo-volcanic features on the seafloor that will later be combined with the seismic data. Later during the day the ship navigated W, closer to Deception island, to proceed with more bathymetric data acquisition. This work will proceed throughout the night and following day.
Tuesday, 26 February 2019
Today the Hespérides was set to explore the Axe Volcano, located just East of Deception Island. This volcano lays right in the centre of a linear ridge system and is a potential host for hydrothermal activity. We have crossed the system early morning using seismic data acquisition, TOPAS (sub-bottom profiler) and high-resolution bathymetry. Based on this information we set up a series of target points, inside the volcano, to further investigate for hydrothermalism by using CTD profiles and gravity corers. The first couple of targets, on top of linear volcanic vent cones inside the main crater, gave seawater column anomalies. We then continued with gravity corers supported by TOPAS information and managed to retrieve ash and coarse volcaniclastic material from the volcano. Total we did 6 CTD profiles and 4 gravity corers. We have now important data that we can use to better understand the system that lays below us. Our plans for the next day is to proceed with the high resolution bathymetry to finally cover the entire section of Axe volcano. Ana Lobato working on the GIS to plan the lines and sampling sites.
Monday, 25 February 2019
Continuing from last night, the day started with sparker seismic data acquisition. Soon after it was decided navigate towards the southern coast of Livingston island to probe curious pot marks visible in the high resolution bathymetry. The location of these submarine features posed a navigation difficulty as they are relatively shallow, and the navigation charts showed rock pinnacles emerging almost vertically in the surrounding areas. Even so and following a careful approach we have done a CTD right the core of the pot mark (roughly 80 m deep) and quickly exit the area to deeper waters. Along day we have made a couple more CTD profiles and 3 gravity corers in an area influenced by an active N-S fault that controls, to the south, the Eastern limit of Deception island. At around 6 pm we have approached the “Juan Carlos I” Spanish base to proceed with logistic operations. Alongside with the ship’s operations the scientific team has been treating and subsampling the water and sediment core samples. This is a fastidious process that requires the involvement of the whole team. We plan to proceed with seismic operations during the night shifts. Professor Cristina de Ignacio from the University Complutense (UCM) describin the cores. At the background, Jennifer Zwicker from the University of Vienna and Natalia Constantinova from the University of San Petersburgh.
Sunday, 24 February 2019
The Hesperides spent the night and morning acquiring high resolution multibeam bathymetric data. At some point we have done another CTD profile and the next steps for the upcoming days were revised in face of the new acquired data and weather forecasts. On route to our next work target, seismic (sparker) we were fortunate to visit Hannah Point in Livingstone Island. This area is populated with penguins, seals and elephant seals and is too an outstanding geological landscape with layered lava flows, trust faults and hydrothermal alteration. The team had a safety and protocol briefing prior to disembark in the island. Amongst many relevant indications we made sure that no contamination was brought to the island. For instance, our boots were washed with a specific product so that no seeds or other alien products would be transferred through our equipment. Upon our return we then started setting up the seismic equipment. The team of hydrographers from the Hydrographic Institute of the Navy (IHM) (on the upper right) have been working in the Punta Hanna Cape.
Saturday, 23 February 2019: Lab working
Early morning was used to treat, characterize, photograph and archive the rock samples taken from “Sail Rock”. Javier Gonzalez and Egidio Marino from the Marine Geology Dv. of the IGME opening the cores. Two gravity corers needed to by open and sub-sampled and this was a task for the following group. The ship is now doing multi-beam bathymetry and this will take the rest of the day and night. Meanwhile the scientists use this time to prepare the work ahead in the Island.
Thursday, 21 February 2019: Deception Island
By mid-morning we have finalized the first set of seismic lines, 17 to be precise. The large volumes of data produced need now to be processed so that the scientists can interpret the structures. We then headed to Deception Island to pick up one of the EXPLOSEA scientists. The sea was again calm and the sky was clear so we could enjoy the magnificent views of the island. On a geologist’s perspective, the volcanic landscape is dramatic and extraordinary with the different lava facies and vibrant colors. Inside the bay we could see steam coming out of the water reminding us on how volcanically active this area is.
We then proceeded to the vicinity of Sail rock. A tall, steep pinnacle of volcanic rock emerging abruptly from the ocean. The team of hydrographers using thick “Viking” suits embarked the zodiac and surveyed the area for several hours to acquire bathymetric data. While on the zodiac, we continued operations on the Buque Hespérides. CTD’s, and the first gravity corer with a successful recovery of ~1m of bottom sediment. We are now going to work all night long doing more CTD profiles on areas of interest and testing dredging operations.
Wednesday, 20 February 2019
The EXPLOSEA cruise is now on full mode. We have been all night and day doing high resolution seismic just W of Deception Island. We are combining data from the multi-beam and sub-bottom profiler eco-sounders with the information provided by and the high resolution seismic to better understand the geological features of this complex area.
For the seismic operations, the ship toes “airgun” and streamers and follows predefined lines at constant low speed (4 knots). This method gives us extremely useful information on the structure of the sub-surface below the seafloor.
The sound waves produced may upset marine mammals, therefore we follow a strict work code to ensure that no harm is done. When initiating the operations, a series of gradually increasing bursts are made in order to signal nearby animals. When and if cetaceans are at sight all operations are interrupted. And so it happened. A group of whales found us too appealing and decided to check on us. We had to cease all operations but, in turn, we had wonderful sightings of whales so close to us that we could hear them.
Thursday, 22 February 2019: Diving into a volcano
This day was arranged to further study the shallow flat volcano from where “Sail Rock” emerges just west of Deception Island. We had now a newly acquired shallow bathymetry produced by the Armada hydrographers. The EMECP team boarded the zodiac with a set of target points for CTD profiles, imaging and sampling. These points layed on top of submerged pinnacles around “Sail Rock”. In parallel the ship run very successful gravity corers and CTD profiles. Once the zodiac team was back on board and the HD videos of the sea-bottom were viewed it was decided to try a new approach for the characterization of the rock substrate. A new team boarded the zodiac, this time with qualified cold-water divers to attempt rock sampling from the shallow portions surrounding the “Sail Rock”. The night shifts were used to continue seismic data acquisition and, very importantly, to prepare the gravity corers for storage, sub-sampling and further studies. This involved in-situ measurements of pH, eH and temperature parameters.
Monday, 18 February 2019 Passing the Mar de Hoces or Drake Passage
We are now in open seas crossing the Drake Passage or Hoces Passage. At 10 am the colleagues of the Universidad de Tecnologia Marina (UTM) gave the scientific and technical team a morning briefing on how to monitor the TOPAS and EIVA equipment while on shifts. These are geophysical tools that will provide valuable information of the sub-seafloor, either by parametric sub-bottom profiling or through processed seismic data respectively.
The EMEPC team (Portugal) spent the day testing their equipment specific for shallow (<200 m) exploration; CTD’s for water column data acquisition, dredges, HD cameras, and Niskin bottles for sampling of seawater. The scientific team discussed thoroughly sampling procedures and work plans in face of the actual cruise timings.
Perhaps the highlight of the day was the sighting of dolphins in the cold Antarctic seas. Marvelous creatures.
Sunday, 17 February 2019: Passing through the Fueguinos Channels (Tierra del Fuego)
Crossing the straights. We are on transit to our work area near the Deception Island. Today we were blessed with stunning landscape on each side of the straights on route to Ushuaia. A series of “ventisqueros”, hanging glaciers, appeared on top of steep mountains that limit the fjords of Tierra del Fuego. There’s no better way to start this cruise than to appreciate how magnificent are the Earth’s dynamic systems.
But not all is sea view. Technical and scientific team are getting ready to the next couple of weeks of intensive work. Tons of material that has been loaded into the ship needs to be unpacked and assembled into the labs prior to transit in open seas where any cargo movement presents enormous difficulties. Another important aspect is the weather forecast. Work plans are revised often in face of updated weather forecasts as only few operations can proceed with less than optimal winds and waves.
Saturday, 16 February 2019: Leaving Punta Arenas (Chile)
Departure day at Punta Arenas, Chile. The wind speed has lowered, after an impressive Friday evening with wind gusts of up to 130 km/h at port. This is the Chilean Patagonia. We have now a weather window that will allow us to navigate south, through the fjords “Fueginos Channels”, and towards the Hoces Straight and Deception Island.
But first, safety. At 15.00 the Captain and Armada crew of the Buque Hesperides guided us through the safety guidelines and rules on board of the ship. There are escape routes towards the life rafts that we need to know. Plus, we have myriad of safety equipment from oxygen mask to Viking dry-suits that will increase our chance of survival in case of emergency.
We are all excited to start our expedition and, weather permitting, we face a bold work plan with numerous scientific questions to address.
