Above, an undated photo of the Vostok drilling complex (photo source)
On 25 January 2015 the Russian news agencies announced that they'd drilled a new clean borehole into the lake. Surprisingly, I've seen only three announcements so far, and none of these to date have been from Western or scientific publications. What is out here...this report from Russia Today (RT), this article from the the Malaysian Digest, and this post from the Russian Geographical Society. The water surface was hit at a depth of 3769.15m/12,366 ft using the current borehole 5G-3 (or 5Γ-3, per graphic at right from the environmental assessment).
Just announcements...no details or photos. Yet. What is almost certain is that Russia will issue more information at the next Antarctic Treaty meeting (XXXVIII, in Sofia, Bulgaria, 1-10 June 2015). Meanwhile, I presume that the Russians used the techniques described below.
(updates after the 2013-14 summer season)
In 2013-14 the drilling activity was supposedly to be limited (Sputnik News/Voice of Russia article). But that proved not to be the case, as once again a significant amount of information was published at the Antarctic Treaty meeting in Brasilia in April. First...a summary of the drilling report: Ten drilling experts, along with members of the 2013 and 2014 winterovers, took part in the drilling activities. The first activity, beginning on 3 December, was a detailed logging of the borehole and a reaming of areas where the diameter was less than 138mm/5-1/2". Narrowing of the borehole was, and will continue to be an issue due to the large pressure difference between the ice and the drilling fluid due to the low density of the fluid. This was due to the shortage of Freon F-141b delivered in January 2013. After more Freon was delivered this season, 850l was added, but the pressure difference between the ice and the drilling fluid near the bottom of the borehole exceeded 6 bars...meaning additional reaming would be required at the beginning of the 2014-15 season.
The core drilling began on 22 December...between then and 2 February, 181m of lake ice core from the borehole was recovered, in the depth range of 3543.56-3724.42m. As the coring activity approached the lake surface, the ice temperature increased sharply...after the last core was recovered, only about 45m of ice remained to be drilled above the ice-water boundary at 3769.3m.
After the drilling operations ended, the drilling winch cable was replaced. The ice cores were shipped to St. Petersburg aboard the R/V Akademik Federov.
Meanwhile...the method for actually sampling the lake water was being developed. In summary, Russia was planning to lower a transport unit containing a small winch (1mm cable) and a capsule (sent down in a chamber filled with ultrapure water) which would be lowered into the lake water. That report is here.
A much more detailed description of the sampling procedure was presented in the IEE titled "Study of the water column of the subglacial Lake Vostok." The planned schedule presented was:
The probing technique: first, there would be drilling through the top of the "ice cork" to within 5-10m of the lake, with injection of additional drilling fluid. The last few meters would be drilled using thermal electric heaters of the transport unit. After the lower portion of the unit contacts the lake water, the lower lid of the transport unit will be opened to allow the measuring/sampling devices to be lowered into the lake. After the measuring/sampling is completed, the exploration module will be lifted back into the transport module by the winch, the lower lid is closed using an electromagnetic lever, and the unit is recovered to the surface.
Because of the need to avoid contamination of the probe, water samples, or of course the lake water, a class 1000 clean room was to be established at Vostok for the opening and examination of the probe modules.
(updates after the 2012-13 summer season)
The project was in the news several times after the 2013 Antarctic Treaty meeting, but I saw nothing published about any test results from the cores recovered in 2012. One bit of news (which emerged in early July 2013) involved research by a group at Bowling Green State University in Ohio...who obtained and analyzed 3,507 genetic sequences (such as mRNA) found in cores of accretion ice (ice originating from the lake which froze to the bottom of the glacier). On 3 July 2013, their results were published in this paper by Shtarkman, Y.M., Koçer, Z.A., et al, in the open-source journal PLOS ONE. The paper was discussed in media reports such as this one from the BBC. The cores had been from four core sections, two designated V5 (from 3563 and 3585 m) and two designated V6 (from 3606 and 3621 m). These cores were probably extracted in 1997-98 as part of the Russian/French/US collaboration known as the Deep Drilling and Ice Core Study; they were obtained from the National Ice Core Laboratory in Denver, CO (more information about the study and laboratory is below).
The ice is moving at only about 3 meters per year, so it takes 15-20,000 years for the ice to move over the lake surface--hence the significant accretion (below, a closeup Russian graphic showing the accretion layer in relation to the borehole). The full graphic includes a listing of the unique gene sequences; 1,623 of the 3,507 sequences were classified taxonomically (meaning that the genus and species of the source organism was identified). About 95% of this genetic material matched from bacteria, but others were identified with multicellular organisms. Some of the identified bacteria was typically found in the guts of fish; others were linked with organisms associated with deepwater hydrothermal vents. Hmmmm. I'm not a glaciologist or a biologist, so I'll leave things here.
The delegation from the Russian Federation presented four papers about the Lake Vostok project at the May 2013 Antarctic Treaty meeting in Brussels. The first of these proposed that the drill structure at Vostok (pictured above; this photo is from their proposal) be added to the official list of historic sites and monuments and named for Boris Kudryashov, the chair of borehole drilling at the St. Petersburg Mining Institute until he passed away in 2002. Boris was significantly responsible for the technology for the successful Lake Vostok drilling project. Ice drilling at Vostok began in 1967; this structure was completed in 1983 to facilitate the drilling of two deep boreholes. Although the existence of Lake Vostok wasn't known when this drilling started, one of these boreholes (5G) eventually became the deepest ice borehole in history (3769.3m/12,366 ft)...into the subglacial Lake Vostok.
The second paper detailed the drill project operations during the 2012-13 summer. The plan was to collect ice cores of the frozen water that had upwelled from the lake, and these operations began on 12 December 2012. The plan was to collect cores; before that could happen, they had to calibrate (determine the diameter of) the borehole below 2200m/7,218 ft and analyze its contents. The borehole was at least 138mm/ 5-1/2 inches in diameter down to a depth of 3199m/10,495 ft (these depths are ice core depths not cable depths); on the next trip, a mud plug was recovered (each trip at this point was about 30m/100 ft). It appeared that when the lake was penetrated, lake water rose in the borehole to this 3199m depth before receding, leaving a layer of ice on the edge of the hole (which was otherwise filled with liquid drilling fluid). From this point, a 135mm/ 5-5/16 inch drill bit was used. The first ice core was recovered at 3417.4m or 11,211 ft...which contained (not unexpectedly) a hydrate of the Freon drilling fluid.
The frozen water layer was reached at a depth 3424m/11,233 ft, after which the first core of lake water was recovered. During the coring operations the drilling rate was 2.2-2.5m/7.2-8.2 ft per trip. At 3537.7m the borehole deviated from the original 5G-2 borehole (from which the lake water had upwelled); below this depth the borehole was designated 5G-3. Operations continued to a depth of 3543.56m/11,625.9 ft. A total of 122.1m/400 ft of core was obtained; from various depths, these contained the hydrates of the mixed drilling fluid, congelation ice, atmospheric ice, or lake ice. The only actual lake ice cores obtained came from the bottom 5.5m/19.36 ft of the coring operation. Meanwhile, the last core from the 2011-12 season, which had not been fully processed that summer, was also analyzed...it included a yellow crust of mineral particles. The lower 3.5m of lake ice was reported to be composed of a single ice crystal.
Other preliminary studies conducted on station analyzed the the composition and conductivity of the transient zone between atmospheric and lake ice, and comparisons of the content of the original borehole to the lake (5G-1) and the 2012-13 hole deviation (5G-3).
The cores were to be shipped back to Russia on the Akademik Federov, with an ETA at St. Petersburg of 10 May 2013. And I expected some further results to have been posted by now...but no. This 9 July Science NOW article suggests that we may have results within the next year. Oh by the way, I'm not a glaciologist...so if anyone reading this page and the referenced papers thinks I missed something or got it wrong, please let me know.
The third paper, titled "Approaches to study of the water layer of subglacial lakes in the Antarctic", provides further details and future plans...with comparisons to the successful USAP WISSARD project to drill into the Whillans Ice Stream, as well as the failed BAS effort to get into Lake Ellsworth. The Russian program had not yet determined when (or how) they'd actually unseal the lake water and collect a liquid sample. They did report that during 2013-14 they'd drill and core the remaining 236m/774 ft of the glacier ice.
The fourth paper presented by the Russian Federation addressed the March 2013 news reports (BBC News article) that unidentified bacterial life had been detected in the Lake Vostok samples. This report was almost immediately debunked as being based on probable sample contamination. But apparently the bacteria was still unidentified, according to this 7 March 2013 rt.com article. The Russian Federation paper also addressed this issue. All I can say (until further news comes out) is that it is still early yet.
The Lake Vostok Success...February 2012
Above, the drillers' hero shot. The sign reads, "05.12.12, Vostok Station, Boreshaft 5G,
Lake at depth 3769.3 meters."
The 2012 breakthrough came at 2025 Moscow time on 5 February 2012, when the drill penetrated liquid water and the pressure forced liquid up through the interior of the drill/hole to the surface (more on that later). The day before, the drill had contacted a small water lens at a borehole depth of 3766m/12,356 feet (and this event was prematurely interpreted by some media sources as an actual penetration of the lake.
Project background and history:
The existence of under-ice lakes was first postulated theoretically by Russian scientist Peter Propotkin at the end of the 19th century--he theorized that the extreme pressure of the ice sheet might raise the temperature enough to cause melting at the ice/rock interface. Russian seismic soundings in 1959 and 1964, during the first years of Vostok occupation, suggested the existence of a subglacial lake. British scientists conducted aerial radar surveys in 1973 which also suggested such a lake. Finally, the ERS-1 satellite confirmed the lake's existence in 1991, and it has been further delineated since then; it is about 250km/825 miles long and 50km/165 miles wide (above left; 1997 Canadian Radarsat image from the NSIDC) (information and high resolution image). The lake is named after Vostok Station, which is in turn named after the Vostok, a Russian warship used for Antarctic exploration by Admiral Fabian von Bellingshausen in 1898-21 (the word "Vostok" means "East" in Russian).
The drilling of deep boreholes at Vostok began in 1989 (the 1989-90 summer season), although they were not originally intended to reach a subglacial lake. After the first four holes of varying depths and diameters were completed, later that summer (19 February 1990) the major project, borehole 5G, was begun. It was started using thermal drills; by 27 December 1991 it reached a depth of 2503m/8212 feet. The drill became stuck during recovery and could not be extracted. After study, the borehole was deflected to a new path at a depth of 2243m/7359 feet, so as to avoid the stuck drill. At this point the borehole was called 5G-1.
At the end of the 1992-93 season the borehole 5G-1 had reached 2755m/9039 feet. At that point Vostok Station was temporarily closed due to funding constraints. Drilling resumed in the 1994-95 season using an electromechanical drill, reaching 3109m/10,200 feet. Efforts continued in the ensuing summers until January 1998, when the drilling was halted at a depth of 3623m/11,886 feet. At this point, the hole was determined to be about 100m/330 feet from the lake surface. At right is a 2001 NOAA aerial photo of Vostok Station showing the drill tower, by Todd Sowers (source and detail).
A schematic diagram of the Vostok deep borehole as of the end of the 2009-10 season, indicating the various depths, deflections, starts, and stops over the years. This graphic was included in the final CEE approved in late November
2010. Here is another earlier version of the graphic which indicates the borehole diameters, types of drills used, and approximate age of the extracted ice cores.
As indicated in the above graphic, the earlier phase of the drilling project was the Deep Drilling and Ice Core Study, a collaborative program between Russia, France, and the US, and accordingly, each of the collaborators received 1/3 of the core. Thus...
The above 2 photos were taken by Melanie Conner in October 2002 at the NICL in Denver, Colorado (and are from the Antarctic Photo Library). They appeared in two November 2002 Antarctic Sun articles; one titled Seeking life in Vostok's deepest ice, which discussed the Vostok drilling/coring projects; and another titled Frozen to the core which described the NICL and its operations.
Back at Vostok...the drilling stopped for almost eight years, and intense worldwide scientific discussions ensued as to whether and how the effort should be continued. The main issue was contamination--for one thing, the hole had been drilled using diesel fuel/kerosene as an antifreeze drilling fluid [I've been unable to determine the true composition of the drilling fluid...in part because of differing English language definitions of "kerosene" vs "diesel." The "kerosene" was identified as an aviation grade (JP-8, which is similar to AN-8) in the 2003 draft Comprehensive Environmental Evaluation (CEE). Some Freon F-141b was mixed with it. however, at least some of the "antifreeze" introduced in the last years of drilling was ethylene glycol, as mentioned in the 2008-09 report linked below]; and there was concern about contamination of the lake with this liquid and/or various organisms it and the drill equipment might harbor.
[At left is a diagram of a thermal drill used for the earlier drilling efforts above 2755m (diagram from the final/approved CEE). It was proposed but not used for some of the later drilling.]
This issue became a significant discussion item among the scientific community as well as at the annual ATCMs. In January 2005, Russia was granted a permit to resume some drilling at Borehole 5G-1 based on the preliminary CEE reviewed by the Antarctic Treaty nations, but after preparing to resume drilling in December 2005 the Russians decided they needed to make further revisions to the drill design. The drilling did not resume until 26 December 2006, at which time the bottom of the hole was at 3650m/11,975 feet. On 14 January 2007 at a depth of 3658.26m/12,002.16 feet, the drill became stuck after the cable broke. The drill was extracted on 7 February after 200l/53 gal of antifreeze was introduced. Efforts ensued to remove as much of the antifreeze as possible. This accident ended the drilling for the season, and it also necessitated further study which delayed completion of the final CEE. Russia presented this information at the XXX ATCM in March/April 2007; their detailed report is here (this and most of the other ATCM reports provided here are MS Word documents).
Drilling resumed in June 2007, going down to 3666.54m/12029.3 feet, when more problems ensued. The power cables failed; the drill support cable broke again after the drill was stuck in the enlarged hole area created by the previous antifreeze addition. The density and level of the drilling fluid was adjusted by adding Freon F141b to the mix, as well as more kerosene. The plan at this point was to divert the bottom of the hole if the drill could not be extracted, and to switch to a thermal drill (details in the 2008 Russian report presented at the 2008 ATCM in June).
In 2008-09 the efforts resumed; in January the attempts to remove the stuck drill failed, so a new borehole was deflected from the main shaft at 3589m/11,775 feet. This new hole was named 5G-2 as indicated in the above graphic. After further difficulties with the antifreeze solution density, several cores were obtained to a depth of 3598.6m/11,806.4 feet; interestingly they contained 1-2mm inclusions of sedimentary rock (season report presented at the April 2009 ATCM.
In 2009-10 efforts were made to adjust the deflection of of hole 5G-2 from vertical to 1.5º to avoid contamination from the ethylene glycol antifreeze used in the earlier drill extraction attempts. The hole was continued to a depth of 3650m/11,975 feet, and an additional core was obtained. Another layer of mineral inclusions was detected (2009-10 report presented at the May 2010 ATCM). Meanwhile, the final CEE was approved in 2010 and officially disseminated on 30 November, although activity was delayed because of the the mandatory 60-day waiting period following its approval. Here's the final CEE; it includes extensive detail, graphics, drill details, and a copy of Permit No. 67 for the drilling. The permit was issued to the AARI on 23 November 2011.
Despite the delays, the 2010-11 drilling continued until 5 February, to a depth of 3720.45m/12,206.2 feet, with 30 ± 20 meters (!) to go before reaching the top of the lake, according to the June 2011 report. And another 2011 ATCM report includes a discussion of the proposed water sampling mechanism--a multi-sectioned pipe with sealable chambers and an electric heat system.
The drilling rate at the end of the 2010-11 season had been 1.8m per day, so the program felt strongly that the lake could be penetrated during 2011-12. Accordingly, the opening season flight arrived on 28 November 2011, and the passengers included seven drilling specialists. After acclimatization to the altitude, the drilling equipment was reactivated, repaired and upgraded. It was also necessary to carefully measure the hole dimensions as well as the specific gravity of the drilling fluid, so that its level could be adjusted to balance against the pressure expected when the lake was penetrated. A geyser was NOT desired. Drilling finally commenced on 2 January 2012...with the deadline for station closing set for 5 February. By 13 January they reached 3738.5m/12,265.4 feet, when progress slowed due to technical problems. Progress resumed on 20 January at a rate of 1.5-2m per day, by the end of January they reached 3760m/12,335 feet. At this point, new ice temperature measurements predicted the ice melting at about 3766m/12,355.6 feet.
At this point one plan had been to use an organosilicon drilling fluid in conjunction with the thermal drill, but due to the drilling delays this would cause vs the scheduled closing flight, the drilling continued using an electromechanical drill. On 4 February, difficulty was encountered with removing the core from the 3766m depth. When it was examined, the outside of the lower portion of the core was "glazed" as if it had been immersed in water. When the drill was next lowered, it encountered a water lens. Several liters were extracted; this froze in the upper section of the borehole (which was about -55ºC). It had been forced upward through small cracks by the lake pressure, which was about 3 atmospheres higher than that of the drilling fluid. Final drilling resumed, and at 2025 Moscow time on 5 February the 135mm-diameter drill bit came in contact with the main lake water, at a core depth of 3769.3m/12,366.47 feet.
At this point it became urgently necessary to extract the drill assembly as soon as possible, as there was limited clearance in the hole, and the water from the lake, forced up into the hole, would immediately start to freeze in contact with the ice surrounding the borehole. Fortunately this operation was started about 4 seconds after the lake penetration, and the extraction was successful. Fortunately, there was no "geyser" at the surface as the water forced its way up the borehole...about 1500 liters/400 gallons of mixed fluid flooded into collection trays which had been prepared at the surface.
After things were shut down, the borehole was measured by the winterover crew...and on 29 February, the measuring drill stopped at a depth of 3176m/10,420 feet, indicating that the water level from the lake had risen about 592m in the drill hole (and subsequently frozen). Other measurements of pressures, drill fluid density, and the water level rise were made, and this data indicated that hydraulic fracturing had occurred (!)--a significant quantity of pressurized drilling fluid had penetrated into the sides of the borehole. This was not part of the plan, but as the report states, "Such process is quite common in drilling of gas and oil wells."
The report of the 2011-12 drilling season described above came from the report Russia presented at the May 2012 ATCM in Hobart...yes, I find the description of the fracking on the last two pages to be of great interest!
This 8 February Sputnik News (formerly RiaNovosti) article includes several photos of the drilling operation as well as this animated infographic (right) which graphically depicts various aspects of the project and the types of drilling operations. It specifically names the drill type used for each portion of the operation. Here's another rt.com article from 9 February with more information and links. A few days later a sample of liquid (in a metal-and-glass case) recovered from the borehole was presented to Vladimir Putin, then the Russian prime minister (14 February Guardian article with photo). He was asked if he'd taken a drink...and he said no. The liquid, obviously contaminated with drilling fluids, had been taken from the borehole before the final breakthrough.
In October, results were released from testing of ice crystals which had been frozen to the drill bit...this testing indicated no detection of native life. Most of the microbes appeared to match contaminants from the drilling fluids, others were comparable to background contamination levels (19 October article from ouramazingplanet.com).
As of mid-December 2012, no recent news was available. Still, it is expected that 2012-13 operations will obtain clean water samples, which may not be available for testing until May 2013. And future efforts will attempt to sample water from lower water depths, or obtain sediment samples from the lake bottom (18 October Nature blog post). Stay tuned...