Reports from the Ross Ice Shelf
To understand more about Antarctica’s potential contribution sea-level rise, our small team of drillers, engineers, and researchers are travelling ~800 km via traverse and airplane to the southeast margin of the Ross Ice Shelf. Once there, they will drill up to 200 m below the seafloor to recover a geological record of changing rock types that reflect environmental conditions at the time they formed. The hope is that these records will provide key insights into West Antarctica’s past and the Earth’s future.
Antarctic field operations are happening on the Kamb Ice Shelf right now led by Tina van de Flierdt and Richard Levy. A second field season will begin in November 2024 at the Crary Ice Rise co-led by Molly Patterson and Huw Horgan. This page will contain updates on what is happening operationally on the ice and a high-level view of what is happening in terms of science. We hope to update this page throughout the season with information from Denise Kulhanek.
Antarctic frontier project ‘tantalisingly close’ to vital climate secrets
Our international team has successfully drilled through 580 metres of ice, obtained the longest sediment core ever retrieved from the remote Siple Coast, and gathered crucial information in our mission to understand the West Antarctic Ice Sheet’s past response to climate warming.
Our deep-field research camp close to the ‘grounding zone’ of the West Antarctic Ice Sheet, where the vast ice mass begins to float as the Ross Ice Shelf, has been the site of a multitude of ground-breaking scientific achievements this Antarctic summer.
Our On-Ice team of 27, comprising scientists, drillers, and crew set up camp at the KIS-3 drilling site 860 km from Scott Base, living and working in tents on ice from late November through to January, as part of the SWAIS2C project, with logistical support from Antarctica New Zealand and the United States Antarctic Program (USAP).
Our mission was hugely ambitious – to obtain a geological record contained in sediment layers hidden under the ice shelf, at depths of up to 200 metres below the ocean floor. To retrieve a sediment core this deep into an Antarctic seafloor requires a custom-designed drilling system (known as the AIDD – Antarctic Intermediate Depth Drill) and has never been attempted so far from a base and so close to the centre of the West Antarctic Ice Sheet.
“We’re at the frontier, drilling through an ice shelf into the seafloor, to acquire sediment samples that no one has previously been able to obtain. It’s cutting-edge science and incredibly challenging work,” says Richard Levy, SWAIS2C Co-Chief Scientist, from GNS Science Te Pū Ao and Te Herenga Waka—Victoria University of Wellington.
The coveted core is expected to reach back hundreds of thousands of years, potentially even millions of years. Such a record would include the last interglacial period 125,000 years ago, when Earth was around 1.5°C warmer than pre-industrial temperatures – similar to the temperatures we are approaching this year due to climate change.
“The West Antarctic Ice Sheet is currently losing mass at an unprecedented rate. It is one of the most vulnerable components in the Earth system to increasing warming. But we fundamentally do not know when and how fast it will disintegrate and raise global sea level by several metres,” says Tina van de Flierdt, SWAIS2C Co-Chief Scientist, from Imperial College London.
“The sequence of rocks in the sediment should tell us how the West Antarctic Ice Sheet behaved when it was a bit warmer than today – if we find marine algae, it’s likely the ice sheet retreated. This information will allow us to build a much better picture of how Antarctic ice will respond to future warming, which parts will melt first, and which parts will remain,” says Levy.
We used a hot water drill to melt through nearly 580 m of ice, breaking through the base of the ice shelf into the 55 m-thick ocean cavity lying between the ice and the ancient layers of mud and rock below.
Our drilling team got underway with the ‘big’ rig – the AIDD – lowering heavy equipment, drill string, and glass reinforced epoxy ‘sea-riser’ tubing through the new hole in the ice, all the while applying hot water to avoid it freezing back over. However, due to technical challenges, operations were halted, and the decision was made to retrieve the equipment and end deep-drilling operations for the season.
Levy says having tested the equipment in the field, the team now know the modifications – a relatively simple fix – that are needed to improve the chance for success when they return next season.
“This year we got tantalisingly close. With the knowledge we’ve gained from the samples collected and the technological experiments conducted, we have an excellent chance next year to recover the long sediment cores to provide the climate insights we’re chasing.”
With the AIDD parked, our team innovated using other coring methods – including the physically demanding hammer coring technique, in which a rope is pulled to hammer attached weights up and down and drive a steel tube into the seafloor to collect sediment. With all hands on deck, we were able to recover a 1.92 m core – a record for the Siple Coast – as well as 9 shorter cores.
“These samples offer a huge increase in the amount of material we have to help us understand the present-day environment beneath the ice shelf, and the history those sediments represent. They also give us insight into the types of rock we will need to drill through to get those deeper records we’re seeking,” says Levy.
The samples will also be studied for their microbiological content to reveal more about the microorganisms living in the unique cold and dark environment.
The ocean cavity itself holds important information, and oceanographic data was gathered with a device (CTD) to measure salinity, temperature, and density in the ocean. We also deployed a long-term mooring with a range of oceanographic instruments to collect data about the ocean currents and properties at the grounding zone for years to come. Such observations are far and few between in the Ross Sea and will allow the scientists to understand if and when warming ocean water around Antarctica will eventually cause the water that flows below the ice shelf to warm and increase melting at the grounding zone.
Preparations are already underway for the next season when SWAIS2C will return to the site armed with the new knowledge and experience we have gained.
“We are thrilled with what we’ve achieved. It’s a massive step forward towards our ultimate goal to recover the sediment we need to answer the big questions that are crucial for humanity as we adapt and plan for sea-level rise,” says van de Flierdt.
End of the first season at KIS-3
The first SWAIS2C field season at the KIS-3 drill site on the Ross Ice Shelf is over, and our on-ice team is heading home with some cool new data and invaluable on-site experience as we continue our efforts to recover long sediment cores at our two study locations.
Twelve scientists, 10 drillers, and 4 camp staff deployed to the KIS-3 site in late November through early December 2023 and set up an efficient camp comprising many sleeping tents, a mess tent, three science facilities (tents and container), and a large drilling tent.
Hot water drilling through ~580 m of ice went exceptionally well, and we broke through the base of the ice shelf into the ocean cavity just before Christmas. Our first science activities through the open hole began immediately. Over a twelve-hour period we were able to collect several sediment cores using a gravity corer, acquire oceanographic data during several CTD casts, and collect video camera footage from the seafloor and the bottom of the ice shelf.
On December 23rd, the Antarctic Intermediate Depth Drill (AIDD) was moved into place. Our drillers had deployed ~80 m of drill string, including the heavy steel bottom hole assembly and many lengths of sea riser made of glass reinforced epoxy, when we had to halt operations due to technical challenges. After careful consideration of all options and risks involved, our leadership team decided to end drilling operations for the season. Our drillers were able to safely retrieve all drill string, and we have very clear options to modify our operations to mitigate the technical challenges we experienced this year.
Once the ice shelf hole was clear of drill pipe, we started another phase of open hole science activity. These included additional gravity coring and a series of continuous CTD casts over a 24-hour period.
On December 28th, we deployed a hammer corer and recovered a 1.92-m long core, a record for the Siple Coast. This success was due to several innovative modifications to the core catcher and our deployment technique that were suggested and implemented by members of our drilling team.
We finished our borehole science operations with a successful deployment of an oceanographic mooring that will collect important data from the ice shelf cavity over years to come. These new data add to a sparse but growing body of measurements that are key to understand if warming of the Southern Ocean will cause the Ross Ice Shelf to melt.
Several of our team members also took time to uncover GPS equipment and ice penetrating radar (ApRES) that had been buried by several years’ worth of snow at two sites close to KIS-3, which were occupied by New Zealand colleagues at previous science campaigns in preparation for SWAIS2C. Data have been downloaded, and we are looking to redeploy the equipment at KIS-3 prior to final camp pull-out. We also moved some consumables that will be used for seismic experiments at Crary Ice Rise, the second drill site of SWAIS2C, now targeted for drilling in the 2025/2026 season.
We have achieved much this season and have learned a large amount about our challenging drilling process and environment. This new knowledge can only be gained through a field-based ‘shakedown’ and will ultimately help us achieve our goal to drill deep below the seafloor in this poorly understood region of Antarctica. We were thrilled when the almost two-meter-long sediment core arrived ‘on-deck’. In all, we return from the Ross Ice Shelf with 8 gravity cores and 3 hammer cores and a total 7.6 m of sediment.
Obviously, we want more, but the cores we did recover provide a new record of recent ice sheet and ice shelf retreat, a climate and environmental record that will be studied in detail over the coming months. We also have lots of sediment samples that will be studied for their microbiological content so that we can reveal more about the communities living in the extreme environment below the cold and dark ice shelf cavity.
And finally, we now know that the sediments below the seafloor at KIS-3 are relatively soft and that we can use our hydraulic piston corer with confidence – a big step forward as we sort important details for our drilling campaign. As the calendar crosses from 2023 to 2024, our team is already preparing to return to KIS-3 in November to complete our sediment drilling objectives. We can address the technical issue encountered with the AIDD system this season. Our drillers, engineers, and scientists have gained significant hands-on field-experience with both the hot water drill and the AIDD system, and how they ‘connect’. We can’t wait to return for the 2024/25 season!
Tuesday 26 December 2023
What is an interstitial water sample and why do we care? Sediment deposited below the seafloor often contains a lot of water, which is called interstitial water or porewater (because it is found in the spaces between grains in the sediment). Geochemists can study the composition of the water to learn about processes happening in the sediment after deposition. For instance, changes in pH (acidity) of the water can dissolve some particles.
Microbes also interact with the sediment and water as they use different compounds energy, which can also result in changes to the sediment composition after deposition. For scientists who want to use sediment to understand past climate, it is important to be able to figure out if our sediment records represent conditions at the time of deposition, or if these processes after deposition have changed the record.
Geomicrobiologist Alex Michaud studies the interactions of microbes, porewater, and sediment. To do this with the sediment cores we’re collecting here at the KIS-3 site, he has extracted porewater using a tool called a rhizon, which is similar to a small syringe that is inserted into the sediment at different places to remove the water from the sediment core.
Monday 25 December 2023
Merry KIS-mas from the SWAIS 2C Team!
We here at the SWAIS 2C KIS-3 camp wish everyone a happy and joyful holiday season!
Sunday 24 December 2023
Today we took a little time to make our camp feel a bit more festive in preparation for Christmas! Although we won’t have our official Christmas dinner until we can all celebrate together (after we are finished working different shifts), we still had some special treats prepared by our chef Rayanna, including Christmas sugar cookies and fruit cake. It also included White Christmas, an Australian Christmas treat made of puffed rice, dried coconut, powdered sugar, dried milk, and mixed fruit.
We voted and, since most of the camp considers the movie “Die Hard” a Christmas movie, we had a showing of it in the mess tent! Amongst the festivities, we continued with initial characterization of the gravity cores, which included X-ray imaging, smear slide observations to look at microscopic composition, and analysis of the microfossil assemblages for an initial assessment of age.
Saturday 23 December
Our team are on the largest shelf they can think of, and it's nearly Christmas (for those who celebrate). So of course there needs to be an elf!
Since we can’t celebrate with our family and friends at home, we do our best to celebrate together on the ice. And this year we're doing with it an Elf. We are happy to report Elf is joyously helpful here on the Ross Ice Shelf.
What do elves do on the biggest shelf they've ever seen? Everything from gazing at the beauty, to being inducted into driving a dingo, fixing a generator, directing coffee breaks, and trying to go for a dip in the flubber.
More photos of the Elf on the Ross Ice Shelf's adventures are here.
Friday 22 December 2023
The larger hole (~35 cm) through the Ross Ice Shelf was completed today!
We then had a short window to collect some data and samples from below the ice shelf before the start of drilling operations. This included deployment of the CTD and cameras to collect information about the seawater cavity below the ice shelf, and we also took several gravity cores to collect surface seafloor sediments.
Gravity cores enable scientists to sample and study sediments from the seafloor reliably and at relatively little cost. They get their name because they use the force of gravity to help the instrument sink into the seafloor. The gravity corer we are using here is a relatively simple device with a short (~1 m long) plastic tube that attaches to a holder topped with heavy weights.
The gravity corer is lowered down the ice hole on a cable. As it nears the seafloor we increase the speed of the winch lowering the cable as much as possible so that the gravity corer is “falling”, allowing the plastic tube to sink into the seafloor sediment. We then pull the device back to the seafloor with the sediment held in the tube by piston action. Our drillers are particularly interested in the surface sediment to help with positioning the sea riser in preparation for drilling.
Thursday 21 December 2023
It’s the small luxuries… Remote field work in Antarctica often involves going weeks without a shower or clean clothes. Fortunately for us at the SWAIS 2C field camp, hot water drilling operations mean that we do have hot water for showers, not just baby wipes! We also have a very small washing machine that we use to wash clothing that sits next to the skin. There are several ways to dry the clothes: freeze drying, hanging them on one of the hot water lines, or hanging them next to one of the heaters in the various tents. Regardless of method, having a hot shower and putting on clean clothes after a couple of weeks without feels magical!
The shower and washing machine are set up in the corner of the drill tent, so currently doing some laundry is a great way to interact with the hot-water drilling team to find out more about how it works and see the progress! If we didn't have the hot water drill, we'd have to do our laundry by hand like this.
Wednesday 20 December 2023 (part 2)
After years of planning and preparing and so much hard work of so many, including three weeks of set up time, trouble shooting and dry runs of hotwater drilling (HWD) and sediment drilling (AIDD) systems, our team has broken through the ice!
The hot water drill has successfully melted through almost 590 m (1,935 ft) of the Ross Ice Shelf and broken through its base to reach the ocean cavity below. Congratulations, KIS-3 Team! The drillers successfully made the small pilot hole through the ice shelf and are now “reaming” the hole to increase the diameter to 35 cm so that the tools we will deploy can fit through it.
After widening the hole, we'll take water samples & deploy the CTD, which measures conductivity (which will tell us the salinity), temperature, and depth of the ocean cavity. Then it will be time for to position the drill rig over the ice hole to deploy the riser and start coring with the AIDD system.
Wednesday 20 December 2023
When the wind blows…
After a beautiful day on Tuesday with sunny skies and very little windy, today started out grey and windy and it kept getting windier and colder throughout the day.
By early afternoon, those of us working in the “warm” science tent decided that it was very poorly named as the heat generated by the stove was not enough to keep the cold at bay. What to do then? Move to the mess tent, which has a larger heater for Linda Balfoort, Jae Ill Lee and Arne Ulfers and plenty of hot water and warm drinks to help us get through the day!
We also learned a technique to warm up our hands from oceanographer Ollie Twigge, who has spent several seasons on the sea ice. It involved flexing our hands (to help increase blood flow) and then rapidly shrugging our arms up and down. We might have looked a little silly but it seemed to help! The wind blew quite a bit of snow around, so after it died down, Ollie and Jim Marschalek shoveled some back around the base of the science tent to provide us with better insolation.
We were also visited by 3 skua, who seemed quite interested in the drill tent, where good progress is being made on the hole through the ice shelf.
Tuesday 19 December 2023
Once the hot water hole is completed through the Ross Ice Shelf, we will have about 12 hours to do science operations in the ocean gap between the ice and the seafloor before the drilling team begins deploying the riser pipe.
While we are working in between the ice and the ocean floor, we will be using a CTD. This stands for conductivity, temperature, and depth and it refers to a set of instruments that can measure these properties in the ocean. A CTD device’s primary function is to detect how the conductivity and temperature of the water column changes relative to depth. Conductivity is a measure of how well a solution conducts electricity and it is directly related to salinity. By measuring the conductivity of seawater, the salinity can be derived from the temperature and pressure of the same water. The depth is then derived from the pressure measurement by calculating the density of water from the temperature and the salinity.
A CTD is deployed through the water column (often from an oceanographic research vessel), but we are dropping it through our bore hole using a winch.
In addition to the CTD instruments, NIWA oceanographer Ollie Twigge has attached a camera and lights to the frame that will be deployed into the ocean through the ice hole in order to image the base of the ice and the seafloor.
We hope to be able to show you what we find in this ocean space some time soon.
Here's the entire KIS-3 Team outside the drilling tent.
Back row: Martin "Paddy" Loughney, Rob Teasdale (Antarctica NZ), John Hillock (Antarctica NZ), Jason Coenen, Arne Ulfers, Richard Levy, Tim McPhee, Sean Heaphy, Darcy Mandeno
Middle row: Hedley Berge, Jenn Danis (Antarctica NZ), Tina van de Flierdt, Veronika Meduna, Gavin Dunbar, Jane Chewings, James McPhail, Tony "TK" Kingan
Front row: Ollie Chappell, Denise Kulhanek, Jae Il Lee, Jim Marschalek, Ollie Twigge, Rayanna Francis (Antarctica NZ), Linda Balfoort, Alex Michaud, Adam Rutten
Monday 18 December 2023
Hot water drilling operations started today!
The first step was to drill the pilot hole to 82 m and install the well pump, which was completed by the end of the day. The well pump is used to re-circulate water for making the main hole all the way to the seafloor. During the day, the scientists continued preparations for the start of our initial science activities prior to AIDD drilling, which will include collecting a water column sample, deploying a CTD, and collecting one or more gravity cores after the hot water hole through the ice shelf is completed.
Sunday 17 December 2023
The Antarctic Intermediate Depth Drill (AIDD) has three coring systems that we can use: a hydraulic piston corer, a push corer, and a rotary corer. Piston and push cores are collected in plastic PVC core liners, whereas the rotary corer collects the core directly in the core barrel, which is then extruded onto core liner that has been split in half. The other half of the liner is placed on top and then the core is wrapped to hold it in place during shipping.
We will split the cores during our core description workshop early next year.
Saturday 16 December 2023
Undertaking a drilling project of this scope in a remote area along the Siple Coast of the Ross Ice Shelf requires a lot of careful preparation and a well-designed camp.
The main structures of the camp include the mess tent (kitchen/dining/gathering place), 3 science areas (warm science tent, warm blue container, and cold science tent), and the drill tent and staging area. Also critical are our two toilet facilities and “canvas town”, where our tents are set up. We also have several vehicles used during the traverse that are important for moving snow and large objects around the camp and a green container that serves as an office and emergency medical facility.
Sedimentologist Jae Il Lee has put her creative talents to use to create a beautiful illustration of our KIS-3 camp layout.
Friday 15 December 2023
An important part of the Antarctic Intermediate Depth Drill (AIDD) system is the sea riser, which helps to support the drill string when drilling from floating ice. The sea riser is made of glass reinforced epoxy (GRE), a type of fiberglass that is lighter weight than traditional steel casing. It is designed to provide drill string support for ice platform movement, including both lateral movement (from currents) and vertical movement (from tides).
Each GRE sea riser pipe is approximately 3 m in length. Our drilling team has carefully measured each segment and then connected two segments together into 6 m lengths in preparation for deployment after the hot water hole has been drilled.
Thursday 14 December 2023
Preparations are gearing up to begin operations soon. Once all of the equipment is set up, tested, and ready to go, the first thing we will do is melt an ~30 cm wide hole through the Ross Ice Shelf, which is approximately 590 m thick at the location of our drill site. This operation uses hot water jets to melt the ice, so we need to have a lot of water at the surface for the start of this operation.
Flubbers to the rescue! These large, yellow, collapsible containers hold 12,000 liters of water. To make the water, they are filled with snow that is melted with water from a much smaller container with heating elements. Now the flubbers are full, we are almost ready to start.
Wednesday 13 December 2023
Where do you go when you need to go on the Ross Ice Shelf?
A popular question from friends and family about life in the deep field in Antarctica is where do you go when you need to GO? With a total of 27 members now at the SWAIS2C KIS-3 drill site, we needed more than the “Turdis” (our blue “outhouse” toilet facility) to keep everyone comfortable. Fortunately, science team member Jason Coenen has excellent snow construction skills, today he completed construction of our second facility, called the “Nautilus” due to its spiral shape.
Each facility has a urinal for those that prefer to pee standing up, as well as an “en-suite” for those that prefer to sit to pee. Solid waste is collected in bags in a bucket so that it can be taken back to the mainland at the end of the field season!
Tuesday 12 December 2023
Antarctica is the driest place on Earth, so even though it is cold, we have to drink a lot of water to stay hydrated here. As our water bottles remind us: hydrate or die!
But where do we get water in the middle of a frozen ice shelf? We cut and retrieve blocks of snow with a dedicated saw, shovel, and gloves (to avoid contamination). We use a sled to collect the snow blocks and then move it back to the mess tent where this is a large covered container with heating elements in the bottom.
After moving the sled back to the mess tent, we shovel the snow blocks into the blue container. The heating elements melt the snow, providing us with fresh water that we can drink and cook with. The water is pumped into the mess tent, where it feeds a spigot to fill water bottles and pitchers, as well as a small sink that has both cold and hot water for cooking and doing dishes.
Monday 11 December 2023
Today the science team members still at Scott Base got up early and waited for the go/no-go announcement for the flight to the drill site. At around 7:30am, they got the good news that the flight was a go. The team helped get all of the gear into the vehicles for transport to Williams airfield, and then helped to load the gear onto the Basler plane. After fueling, the team enjoyed a very smooth 2+ hour flight to the site, where the co-chiefs were waiting to greet them!
Sunday 10 December 2023
The Antarctic environment poses many challenges to deep field operations, including scientific drilling for the SWAIS 2C project! In preparation for creating the hole through the ~590 m of Ross Ice Shelf using a hot water drilling system to access the sediments below with the Antarctic Intermediate Depth Drill (AIDD) system, two members of the drilling team excavated a “cellar” below the area where the two drilling systems will be set up.
This cellar, which is 3 m deep, will allow space below the rig floor for various activities, including hanging the sea riser – the fiberglass pipes that will run from the surface to the seafloor and through which the drill string will be deployed. The temperature at the base of the cellar is -35.3°C!
Saturday 9 December 2023
One of the most important things at a remote camp in Antarctica is feeding all of the people at the camp! Scientists Jason Coenen and Gavin Dunbar dug out a freezer in the snow using shovels and a bucket to remove the snow. Once the underground area was prepared, Alex Michaud kept the inventory while Jason, Gavin, and Richard Levy moved food into our deep-field freezer.
Much of the food was brought out during the traverse, but additional supplies (including fresh fruits and vegetables) can be sent by plane during personnel transfers or other planned trips. We can also sometimes get resupplied from planes that need to stop by our site to refuel on their way to other locations.
Tuesday 7 December 2023
All of the camp structures are set up, connected to power, and working well! We also completed the food inventory and stored everything away. With camp set up, the science team has been working on plans for shifts and the core handling process once drilling begins.
The most exciting thing that happened today was the return of the mini-traverse team, who traveled to the KIS-2 site to retrieve the hot water drilling system, which is the last of the gear needed before we can begin operations. Everyone pitched in to help offload the sledges and work has begun getting the equipment set up .
Number of people at Kamb Ice Stream Camp #3 (KIS3): maximum population of 27 people.
Number of tents at KIS3: 22 personal tents, 2 science tents, 1 drill tent, 2 ops tents
Number of hard-sided structures at KIS3: science warm store, living module, general shed
Distance as the crow/Basler flies to KIS3: 880 km
Distance to the nearest open water from KIS3: 480 km
Ice shelf thickness: 595m ±12m
Ocean cavity thickness: 50m
Tidal range: ±1.2m, 2.4m tidal range (CATS model vertical displacement)
Traverse route
The traverse is 1,138km long and relatively flat. A safe route has been planned via satellite imagery and GPR route-proving. We expect the traverse to the KIS3 drill site to take 14 days, barring any weather delays. The Traverse can continue moving where it is safe to do so in restricted visibility. If visibility is too poor (with blowing snow) the group will have to stop until conditions improve.
The SWAIS2C convoy consists of 3 Pisten Bully 300s pulling sled and a living module. Pisten Bully 300s are vehicles that have tracks rather than wheels. They are able to move/push snow, groom skiways, and pull up to 50 tonnes of cargo each. Two of the Piston Bully 300s on this traverse have cranes on the back for moving heavy cargo on and off sleds.
Six Antarctica New Zealand staff are participating in the convoy.
Time needed to make a hot water hole: 48 to 72 hours (approximately)
Amount of hot water used: As an educated guess (with an assumed bore hole diameter of 350mm and total ice thickness of 600m), we will start with 12,000 litres seed water. Then it will take around 72,000 litres to get the well in, then the main bore hole will take another 57,730 litres. So, in total, approximately 130,930 litres
Speed of the hot water drill: At maximum we can pump 180 litres per minute, but nominally we sit around 100 litres per minute. However, once we have the well pump installed, we return water to the surface, so the volume of water roughly equals the volume of ice drilled.
Temperature of water when it exits the hot water drill nozzle: This depends on what depth we are at. At the surface water temp at the manifold (the last location we measure it before the main hose and reel) the temperature is approximately 70-75deg C. We have never measured water temperature in real time down hole while drilling, so we don’t know how much heat is lost in the hose before it gets to the nozzle. We are measuring this info this year so will have a closer approximation.
