Drilling Update From Subglacial Lake Whillans
Here’s an update from WISSARD Chief Scientist, John Priscu (Montana State University), sent late this afternoon (Sunday, January 27th here in Antarctica). This report covers drilling operations Friday, Saturday, and today. The photograph below shows John, at work prepping instruments in one of the labs at the SLW field camp/site.
Drilling continued on 25 and 26 January. The drill encoder indicated a depth of 796 meters in the early hours of 26 January. The drill was left at this depth for several hours to enlarge borehole diameter in this region. The drill was then pulled from the hole at about 0400 h (4:00 am, 26 January) and the mothership team began preparing to deploy this tool to provide a live video feed of the borehole to the surface.
The mothership was deployed at 0555 h (5:55 am, 26 January) with the borehole return pump and power cable still in the borehole, which posed an obstacle to deployment. The drillers adjusted the return pump lines and the mothership was successfully deployed at 0805 h (8:05 am). The tool was lowered at a rate of 10 to 20 meters per minute.
This is a photo Reed Scherer took of the live video feed on his computer screen. It is so awesome to look down the borehole with this instrument.
As the mothership camera reached 690 meters we observed that the latest drill deployment formed a deviation (an irregular feature) from the main borehole. It was clear that this situation would compromise deployment of borehole science tools (putting science tools down the hole) so we decided to melt in this region for several hours, hoping that this would coalesce the two holes (melt the two holes together). Borehole water level sensor revealed that the lake has not been penetrated.
Reaming in the region near 690 m continued throughout the day and the mothership was again deployed at about 5:00 pm on 26 January and revealed that the deviation remained at about 690 meters. The drill was lowered once again to ream the borehole below 690 meters and continue deepening of the hole.
At 0804 h (8:04 am) on 27 January the water level in the borehole rose rapidly from 110 m to about 80 m, with the latter being the estimated equilibrium water head in the lake based on available ice and firn thickness data. At the same time, the load cell showed a drop of 100 pounds. Both real-time sensor readings are consistent with connecting the borehole to Subglacial Lake Whillans. Initial estimates imply that the ice is 801 m thick above the lake, which agrees very well with the prior estimate based on seismic imaging (802m) published by Horgan et al. (2011).
The drillers will continue to ream the hole throughout the day. We plan to deploy the mothership on the evening of 27 January to verify that the lake was penetrated, determine if the borehole diameter is appropriate for tool deployment, measure the thickness of the ice over the lake, and measure the depth of the lake.
The borehole science teams are preparing instruments to retrieve water and sediment samples and data sensors, and borehole tools to collect longer-term data above the lake.
As of this posting, I still do not have final confirmation that the lake was penetrated, but I expect to have news for you tomorrow.
Meanwhile, scientists continued their preparation of instruments for clean sampling procedures. Ross and Tim are shown below, in the same clean suits as I share with you two days ago. They are following strict protocols (rules) for clean access and sampling of subglacial Lake Whillans.
This photo shows Brent (front with hose), filling up a portable container with hydrogen peroxide to take back to their on-site laboratory. The hydrogen peroxide is used to clean the tools/instruments. Mark is in the background.
Brent (front right) and Robin (background) working on the drilling deck, readying an instrument for later deployment.
I shared this photo of Dan a couple of days ago, BUT at the time I only had a black and white version. When I got a color copy I noticed that the seismic information is color coded.
This is another great photo of tent city, SLW field camp. You can see the containers and drilling area in the background.
Thanks to Reed and other WISSARD’s who have sent photos in the past two days. We need more!!! I wish I was there. We might be flying out tomorrow…but weather here today has been windy, cold, and SNOWY again. There is low visibility and everyone’s pretty much stayed indoors all day.
Yesterday I took “Flat Stanley” on a walk around Hut Point. For those of you who don’t know about Flat Stanley, he is a character in a children’s book. There are Flat Stanleys all over the world right now….traveling and reporting on their location. Here are some of my fun photos of Stanley around McMurdo. Mrs. Rebella’s class, from Denver, Colorado….here is your little guy! Enjoy and I’ll be back with more news on WISSARD tomorrow!
Ad we made our way to Hut Point, Stanley noticed these containers on skis. They are used out on the ice.
Stanley enjoyed the view of the open water and ice from Hut Point.
This photo shows the coast of Ross Island and Big Razorback Island in the distance.
Stanley and I posed together at Vince’s Cross.
Stanley was extremely interested in Robert Scott’s hut from the Discovery Expedition in 1902, so we went closer to take a look.
We learned a lot from this sign. Stanley loves reading and learning!
He was very curious, so he peered in the hut through this window.
Stanley was all smiles (as usual) when he saw all of the cool historic artifacts inside of this hut. There were a lot of old supplies, tools, and bits of equipment. There was also some food in there from way back in the early 1900′s when early explorers came to this region.
Yuck! Stanley was not impressed with this dead seal outside of the hut. It’s been there for many years and hasn’t completely decayed.
Here is today’s weather. It snowed much of the day and was very cold and windy. Our roads were blanketed in white once again.
Our conditions after dinner were still very poor. I spent all day working indoors today.
Remember to check back tomorrow to read more about the WISSARD scientists and the drilling operations.