To Useful Island!

To Useful Island!

March 6th, 2017

IMG_8129

Amanda Ziegler and Oyvind Lundesgaard carry gear down from atop Useful Island to the zodiacs waiting below. Photo credit: Krista Tyburski

Today we had a disappointing mooring “recovery”. We located the 200m mooring in the Gerlache Strait and sent release signals to the seafloor. The releases confirmed they had released and we waited eagerly to see the floats rise to the surface. Ten minutes passed. Twenty minutes passed. No floats. The mooring has 2 acoustic releases as a fail-safe in case one of the releases failed in some way during deployment; the second release could still allow us to recover the mooring. So, a release signal was sent to the second release. It too responded, confirming release. Again, we waited. No sign of the surface floats. Communication with the releases showed that the mooring wasn’t moving from the seafloor. Was it fouled? Did some of its floatation fail, keeping it at the seafloor rather than bringing it to the surface? There is no way to know since we cannot see the mooring >200m below us. In hopes that the tides would break the mooring free, we waited for several hours while triangulating its exact position and determining whether it was rising from the seafloor.

Ferrier Useful Penguins

Chinstrap penguin colony on Useful Island. Juveniles are still molting losing their fluffy down to become streamlined like the adults. Photo credit: Cara Ferrier

In the meantime, it was decided that we could quickly multi-task and send zodiacs to nearby Useful Island to remove one of our Automated Weather Stations (AWS). Everyone quickly assembled and geared up for a trip ashore. We all grabbed our waterproof gear for the boat ride, water, snacks, changes of socks, gloves and clothing, a hot drink, and our floatation jackets. We loaded into the zodiac and set out for Useful Island. For those of us who had set up this station a year ago, the site now looked drastically different. There was very little snow and instead, the island was entirely rocky terrain covered with penguins and fur seals. We pulled up to the landing site and the rocky island towered above us. This would be tricky. Perhaps our beloved “Useful Island” wasn’t so Useful!

OLYMPUS DIGITAL CAMERA

A Gentoo penguin nearby as our team dismantles the weather station. Photo credit: Cara Ferrier

The weather station atop Useful Island is comprised of 2 solar panels, 12 x 75lb batteries (much like a car battery), a tripod holding an anemometer to measure wind speed and direction, as well as relative humidity, temperature, atmospheric pressure, and irradiance sensors. This station has been sending real-time weather data via satellite every 15 minutes since it was first deployed in December 2015 but it was time for it to come down. The station was disassembled and had to be hand carried down the 250 m rocky island to be loaded into zodiacs and sent back to the ship. We carefully carried the gear down the rocky slope, dodging penguin nests, Skuas flying overhead, and the sunning fur seals at the landing site. After only 3 hours, we had managed to haul all of the gear off of Useful Island. Looking back at the island from the zodiac and reminiscing of the installation trip over one year ago, I realized that perhaps it lived up to its name and been a very useful site after all!

IMG_5229

Loading cargo into the zodiac to bring back to the ship after dismantling the weather station. Photo credit: Danny McCoy

Advertisements

It’s a Trap!

It’s a Trap!

March 2-5th, 2017

 

After successfully recovering the entire radar station at the Wauwerman Islands, we headed out to Hugo Island and our shelf site, Station B (St. B). We had waited for a few days watching for better weather in order to approach Hugo Island, which is notoriously difficult to access because of rough seas for the small zodiacs we use to get from the ship to the islands. The seas had calmed, the wind died down and we had our window of opportunity. A team set out for the island to repair a GPS station (similar to the one we visited at Vernadsky Station earlier) and to remove a no-longer functioning weather station. After only a few hours, the team had accomplished its goals and the cargo was brought back to the ship. With good weather still on the horizon, we made our way out to St. B to retrieve our first sediment trap.

IMG_2016

Scientists look on as the floats of our sediment trap mooring rise to the surface. Photo credit: Amanda Ziegler

IMG_2030

Stunning weather during our sediment trap recovery in the middle basin of Andvord Bay. Photo credit: Amanda Ziegler

Upon arrival at St. B, we lowered the transducer into the water and sent a signal to the acoustic releases down below. They responded informing us that our mooring was still where we left it 9 months earlier. We sent a release command and received confirmation that the anchor holding the sediment trap in place to the seafloor had been let go. The trap was now rising to the surface at roughly 40m/min. Scientists gathered on the bridge and the bow with binoculars to look out for the surfacing trap. After 11 minutes, it was spotted! The familiar orange flag and yellow floats was visible straight ahead of the ship. The captain repositioned the ship alongside the mooring slowly so that the techs on deck could hook the float line and hook it into the ship’s winch to haul it on board. Everything came on board smoothly and our sediment trap came back full of the material sinking through the water from the last 11 months.

IMG_2031

The sediment trap being lifted out of the water complete with 21 sample bottles holding the material that sank over it during the last 9 months. Photo credit: Amanda Ziegler

We left St. B and meandered through the Bismark and Gerlache Straits back to Andvord Bay. Our time here has been extremely successful and pleasant so far. We are spoiled with wonderful weather, glassy calm sea conditions and spectacular views. Not a bad place to work! We repeated our acoustic search for our second sediment trap mooring and found it sitting happily on the seafloor in the middle basin where it was left. Recovery went very smoothly and revealed full bottles again. Last year, we had also placed cylindrical traps on the line below the sediment trap hoping to capture some material if the trap failed. These cylinders seemed to work great and yielded additional samples for us.

IMG_2033

The cylindrical traps we designed in the event the conical trap above failed. Photo credit: Amanda Ziegler

With 2 of the 3 benthic ecology moorings retrieved, it’s time to pick up more physical oceanography moorings. The first was recovered smoothly, and all of the data recorded over the past 11 months were downloaded. This process can take almost 12 hours with 2 computers running simultaneously! The instruments do not have a way to communicate data in real-time so they all store data internally. This means that if we do not recover the instrument, we do not get any of the data back either. We learned this well with one of the glacier cameras which we had mounted deep in the inner basin of the fjord facing the glacial front. It was taking photos of the glacier every hour so that we could measure iceberg flux and make other observations while not present in the fjord for most of the year. When we returned to the site to retrieve the first glacier camera, the team found only pieces of the tripod, a battery pack, and no camera. Risky deployments can have the potential to pay off the most, so this was a risk worth taking, especially since our second camera was recovered in perfect condition with lots of amazing data.

2017_03-03_glacier cam hike

Scientists assessing the site of the glacier camera in the innermost part of the fjord. It was no longer there. Photo credit: Lindsey Ekern

Where model and reality meet

Where model and reality meet 

February 26, Andvord Bay 64 50.58S, 62 32.76W

Written by: Dr. Lisa Hahn-Woernle

Hi everyone!  My name is Lisa Hahn-Woernle and I am working on the physical-ecological model of Andvord Bay as part of the FjordEco Project. It is my first time down here and everything on this trip has been super exciting for me so far. February 26 was exceptional though! I woke up at 6 am because I felt the boat speeding up. That meant that the mates decided to return to Howard Island. That ALSO meant that they decided to traverse the entry of the Gerlache Strait around 64 50.0 S, 64 W the whole night. Why would they do that? And why am I so excited about this? Well, I am trying to model the region around Andvord Bay in an ocean model that simulates the water movement as well as the biology in the ecosystem. The main advantage of modelling the fjord numerically is that we can study processes controlling the fjord that we otherwise cannot measure. For example, we can determine how important the winds are in driving water in and out of the fjord, and what effect meltwater from icebergs and glaciers could play on the physical and biological processes. Observations are essential to capture the actual state of the fjord, but they are mostly limited in space and/or time. Even though the model cannot resolve everything that happens in the fjord, it allows us to simulate the full basin over a continuous period of time when we are not present.  This will hopefully help us to understand the greater connections that lead to the snapshots we see in our observations.

ModelDomain

Fig. 1: Model domain in the region of Andvord bay (red needle) and the Gerlache Strait. The coloured countours outline the topography. The model boundary sampled in Fig. 2 is along 64o W between 64.8 and 64.88 º S (northern and deep part of the western boundary).

ADCP

Fig.2: Raw ADCP data passing over the northern part of the western model boundary for 6 times in the night of Feb 26/27 and twice until midnight of Feb 27 (red boxes). From this raw data it is hard to assign a specific location to a measurement. My intuition is that the inflow (positive/red features at the surface in the Ocean U plot) occurs over the deep part of the channel. The outflow would then occur in the shallower regions close to the coastline. The tides induce a strong outflowing current that leads to the reduction of the flow till the early hours of Feb 27. As the tides turn around, the flow picks up again.

We are aiming to model the ecosystem during only the summer months from November until the end of March. To start the model, we need to know what the typical state of the fjord would be in November. For example, what temperature and salinity profiles would be characteristic of the water in the fjord. If the region we modelis closedso there is no water flowing in and out of the fjord, temperature and salinity would be enough information needed to run the model (assuming we had the correct forcings like tides and meterology). As you can see in Figure 1, the region we model has 3 open boundaries: one in the west and two in the north-east. To run the model over several months, we need to have an idea about the water masses that flow in and out of these boundaries. What temperature and salinity do they have, what is their vertical structure, do they flow in or out? All of this will have an impact on the model results of the fjord itself. So, for the past months I worked my way through data of different ocean models and measurements to find information about the typical state of our study region. This includes seasonal signals of the water temperature and salinity, meteorological forcing such as winds and air temperature, tidal forcing, and also the strength and direction of the current that flows through the Gerlache Strait. Data down here are scarce, which makes it hard to define the initial model state and the forcing at its boundaries. The parts I have been struggling with the most are the currents that flow in and out of the region. And this brings us back to the morning of February 26. As the boat travels, an acoustic Doppler current profiler (ADCP) is measuring the currents below the hull. This instrument sends out an acoustic signal and estimates the velocity of the water below (up to a certain depth) based on the Doppler effect of the acoustic signal scattered back to the boat. Pretty neat! So we decided to take advantage of our nights and slowly steam back and forth along the model boundary close to Palmer Station. This way we could repetitively measure the cross-stream structure of the currents over a semi-diurnal (twice daily) tidal cycle. Since boats normally only pass along the currents into and out of the Gerlache Strait, this is a pretty unique data set. The cross-current structure will not only help for the boundary conditions of the model, but also allow us to study the importance of tidal currents in the region. By now, we collected data over 4 nights with 6 to 10 crossings per night, which makes a pretty neat dataset for everyone interested in the currents and tides of the region.

An “Apatite” for Mud

An “Apatite” for Mud

February 21st-25th, 2017

navigate icebergs

The view from the bridge of the Laurence M. Gould as we slowly navigate icebergs at night. Photo credit: Andrew Zoechbauer

The Laurence M. Gould made its way from Vernadsky Station southward to Marguerite Bay slowly navigating through sea ice and larger icebergs. This vessel has a unique shape compared to other research vessels because it needs to be able to break through ice. The hull of the ship is reinforced with extra steel to handle the added force of ice impacts. In addition, it has a shallow sloping hull that acts to direct ice beneath the ship as well as to the sides. In thick sea ice, the bow of the ship rides up on top of the ice which then breaks under the weight of the ship. In thick sea ice conditions it may be necessary for repeated backing and ramming motions to eventually break and push the ice away. These operations reduce the speed of the vessel to as little as 0.5-1 knot (0.5-1 nautical mile per hour) whereas the typical clear steaming speed may be 10 knots or more.

finding box core location

Dr. Craig Smith (Lead PI, FjordEco), Anna Clinger (PhD student, UC Berkeley) and Ken Vicknair (USAP) monitor a bottom sounder surveying a good location to sample with the box corer. Photo credit: Andrew Zoechbauer

After navigating through the ice in Neny Fjord, we arrived at the desired sampling location. Two scientists aboard, Anna Clinger (UC Berkeley) and Matthew Fox (UC Berkeley and University College London) are collecting seafloor sediments with the box core to look for a mineral called Apatite. This mineral has properties which allow the group to determine the temperature at which it was deposited which further informs them about the geologic landscape from which it came. In order to box core in this fjord, however, we needed to conduct a SONAR survey so we could find a soft sediment pool deposited by the glacier inside the fjord otherwise the box core could be damaged by hard rock and we would not retrieve a useful sample. The reflection of sound sent out by the ship tells us information about the seafloor including whether it is flat or sloped, and soft mud or rocky. After running several survey tracks we had located what seemed like a suitable, flat sediment pond. To confirm that the bottom was soft mud and not laced with dropstones (rocks that fall from melting icebergs), we used a camera towed from the ship to take a look at the seafloor. From the camera footage we could see a soft muddy bottom perfect for coring! We repositioned the ship over the location we had surveyed and deployed the box core (see archived posts about how a box core works). 30 minutes or so later, we retrieved a wonderful sediment sample. Back in the lab at UC Berkely, the group will search through the mud for very small grains of apatite and begin to piece together the fjords’ erosion and formation history.

sonar

The real-time record of the SONAR depth sounder showing the seafloor. Photo credit: Andrew Zoechbauer

andrew_zoechbauer_box-core

Anna Clinger (PhD student, UC Berkeley), Dr. Matthew Fox (UC Berkeley and UCL), Dr. Craig Smith (Lead PI, FjordEco) and Krista Tyberski (USAP Marine Technician) around the box core. Dr. Craig Smith is sub-sampling the top 10cm of sediment from the box core on deck to collect animals living in the mud. Photo credit: Andrew Zoechbauer

The group collecting the mud also graciously offered the FjordEco team the top 5 or 10 cm of mud to be used for biology. We then sieved the mud through a 300μm sieve to collect animals considered “macrofauna”. A wide diversity of these animals, such as polychaete worms and crustaceans, live within the mud and can exist in very high abundances and represent a large biomass. The samples we collect from farther south along the peninsula will be an interesting comparison to Andvord Bay.

Matthew and Anna

Anna Clinger (PhD student, UC Berkeley) and Dr. Matthew Fox (UC Berkeley and UCL) collecting mud from the box core. Photo credit: Andrew Zoechbauer

sieve

Sieve containing animals from within the mud that will be preserved and sorted back in the lab at the University of Hawaii. Photo credit: Andrew Zoechbauer

We have now left Neny Fjord and are heading back north along Adelaide Island to our next sampling location in Lallemond Fjord. Here we will once again survey the seafloor and use the box core to collect mud from another glacial fjord. We are spoiled in these fjords with glass calm seas, gorgeous scenery and a bounty of wildlife.

leopard-seal

A leopard seal on sea ice. Photo credit: Lindsey Ekern

Стація Вернадський (Vernadsky Station)

Стація Вернадський (Vernadsky Station) 

February 19th, 2017

Photo 1

Arrival at Vernadsky Station, greeted by Ukranian scientists and local Gentoo penguins (Photo credit: Hank Statscewich)

After successfully delivering cargo and scientists to Palmer Station, we set off southward heading for Vernadsky, a Ukrainian research station. We had sailed from Punta Arenas, Chile with a Ukrainian scientist who was to be reunited with his team when we visited the station to dismantle a US operated GPS station nearby the base.

Photo 2

Ukrainian and American flag flying over Vernadsky Station (Photo credit: Amanda Ziegler)

Upon arrival to the Argentine Islands, we left the Laurence M. Gould by zodiac to travel to the station. We were very warmly greeted by Vernadsky scientists who were eager to show us their facilities and discuss polar science. It was a great opportunity to learn about other science being conducted around the peninsula and a reminder that Antarctic science is an international endeavor; Antarctica has no borders.

Photo 3

The iconic Vernadsky logo on a water tank at the station (Photo credit: Amanda Ziegler)

Photo 4

Our newly acquainted friends at Vernadsky Station! (Photo credit: Liza Hahn-Woernle)

Vernadsky station was first established in 1947 by the United Kingdom (named Faraday station in 1977) and was not transferred to the Ukraine to become Vernadsky station until 1996. The station houses only 12 scientists who remain there for an amazing 6-12 months at a time. Each scientist plays a different role on station from measuring ozone concentrations to making observations in meteorology, seismology, and biology. This station is one of the oldest stations in the Antarctic and the location of the longest air temperature and ozone measurements made in Antarctica (excluding those determined by ice cores). The ozone measurements made at Vernadsky led to the discovery of depleted ozone levels in the atmosphere overlying Antarctica, later deemed the world famous ‘ozone hole’.

Photo 5

The largest ozone hole extent measured in September 2006 by NASA satellite – an alternative method to land-based measurements from places like Vernadsky. The diagram shows the global ozone concentration depicting the “Ozone Hole” over the Antarctic continent (purple color) (URL Wikipedia)

Ozone (O3) is a compound created in the atmosphere from the interaction of oxygen and UV light from the sun. In our atmosphere, ozone acts to shield us from the harmful effects of UV light, though it is toxic to life at higher concentrations including damage to our skin or even our DNA. For example, the Ukrainian scientists shared with us that when they first started observing depleted ozone values at Vernadsky, they had first noticed how quickly one would become severely sunburned if outside for even an hour in the bright sun. Ozone has declined over Antarctica since the 1970s from the destruction of ozone in the atmosphere by human-released compounds such as refrigerants (e.g. CFCs, Freon). The depleted values observed overlying the Antarctic continent is generally referred to as the ozone hole.  This phenomenon, however, appears seasonally in Antarctica because the Antarctic continent has little to no sunlight during the winter, so the greatest depletion of ozone occurs during the spring when there is the greatest amount of interaction between the atmosphere and the sun. Today, the ozone hole seems to be undergoing smaller fluctuations and “healing” since the adoption of the Montreal Protocol banning the use of certain refrigerant chemicals globally. Scientists at Vernadsky continue to monitor ozone daily, producing the longest time-series of ozone measurements in Antarctica. We were all quite excited to be shown the instrument (a spectrophotometer) and meet the scientists behind this world-renowned dataset.

Photo 6

The instrument used to measure Ozone at Vernadsky; a spectrophotometer. (Photo credit: Adina Scott)

Once our work nearby the station was completed, we said goodbye to the Ukrainian scientists and headed back to the Gould. Our transit south to Marguerite Bay will take at least 1 day, depending on ice conditions. Other scientists onboard interested in long term sediment records from the seafloor will be collecting box cores at sites in Marguerite Bay over the next few days.

FjordEco III: Return to the Ice

February 14-18th, 2017

andrew_zoechbauer

The FjordEco team in the square of Punta Arenas, Chile rubbing the toe of the Magellan statue for a smooth Drake Passage crossing. Photo credit: Andrew Zoechbauer

The FjordEco team is back for one final trip south to Antarctica to retrieve our gear deployed on our previous cruises in November-December 2015 and March-April 2016 (check out our archived posts for more info!), and to collect some additional data in Andvord Bay. We set sail from Punta Arenas, Chile aboard the ASRV Laurence M. Gould on February 14th into gorgeous weather. We have had a smooth crossing (so far) of the Drake Passage earning it the (temporary) nickname “Drake Lake”. Conditions aren’t always this calm, however. The Drake Passage can also be one of the roughest bodies of water in the world, boasting winds over 100 knots and seas of >50ft. Seasickness is a very real part of the sea-going oceanographer’s life. All of us onboard have swapped sea stories and shared the tricks of the trade for staying well during our 4-day transit. Some of those onboard will be experiencing their very first oceanographic cruise and have great resources from those who have spent years of their lives (literally) at sea!

The Drake Passage crossing is a great time for everyone onboard to become acquainted. One way to do this is to hold science talks in the lounge. Other less formal ways include evening movies, games, and socializing at meal times. During this 4-day transit, the science parties that will be working together for the next month aboard the ship also begin to plan shifts and work out details of how their goals will be accomplished. Part of these plans include how we all stay safe during our time onboard or when we need to go ashore. The crew holds safety meetings and orientations for the science party so we can become familiar with our new working spaces and be aware the hazards of working on an Antarctic research vessel.

Once we cross the Drake Passage, our vessel will arrive at Palmer Station on Anvers Island along the West Antarctic Peninsula. This is one of 3 research stations operated by the United States. There, we will deliver scientists who will be conducting research onshore for the next 3 months, as well as fresh food and science equipment like newly purchased Reinforced-Hull Inflatable Boats (RHIBs). Palmer Station relies on the Laurence M. Gould as a supply and transport vessel. Our cruise will also end with another stop at Palmer Station to pick up northbound scientists and cargo.

andrew_zoechbauer_palmer

The FjordEco team up on a glacier at Palmer Station on the West Antarctica Peninsula. Photo credit: Andrew Zoechbauer

This year, the FjordEco team will be sharing our time aboard the Gould with 3 other science teams who are also retrieving samples and gear deployed all along the West Antarctic Peninsula. Ship time is expensive and therefore precious and very competitive to get, so to serve as many projects as possible, groups often sail together who are conducting similar operations and visiting similar locations. For us, this will be very different from our last 2 cruises in which we sampled around the clock for only one project. We will also not be collecting many sediment samples and no trawl samples (be sure to look back at those posts for more info on the gear and what we caught!). Instead, we will mainly be removing all Automated Weather Stations (AWS), glacier cameras, and moorings which we deployed last year. It is imperative that we retrieve this gear as all but the AWS self-store the data; if we don’t get them back, we don’t get any of the data they’ve collected since April and we lose the gear! This is a risk we must take to retrieve long-term datasets from the far reaches of the earth and depths of the oceans.

lindsey-ekern_palmer

View of Palmer Station from the Laurence M. Gould delivering the brand new RHIB to station. Photo credit: Lindsey Ekern

Keep posted as we sail farther south and bring you snapshots of our time aboard the Laurence M. Gould. Follow #FjordEco on Twitter and @FjordPhyto on Instagram too!