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More notes for St Clair Cave: August 21-28, 2011, May 8, 2011, January 19-20, 2010, March 19, 2009, Aug 3, 2008, July 29, 2008, June 3, 2006, March 21, 2006, March 21, 2006.

St Clair Cave
November 3, 2012
Team: Adam Hyde, Jan Pauel, Ronald Stefan Stewart
Notes: RS Stewart
Video (283 MB MP4)

Hyde and Stewart, Nov 3/12 - Photo: J Pauel
On October 24, 2012, Hurricane Sandy passed over the eastern part of the island at Category 1 strength. Rains in the Ewarton areaa of St Catherine were moderate, but the total accumulation was enough that, in combination with heavier rains during Tropical Storm Isaac in late August, there was a possibility that St Clair Cave had experienced a flushing event in the Inferno passage. In addition, Worthy Park Estate would not resume pressing cane until early 2013, and there was no input of sugar, with an associated high Biological Oxygen Demand (BOD), in the Acheron passage. This seemed to be an opportune time to attempt further exploration of the Acheron, so a visit by Hyde, Pauel, and Stewart was scheduled for Saturday, November 3.

A brief overview of the discovery, and explorations of the Inferno+ and Acheron River follows:

In January of 2005, a team consisting of McFarlane, Christenson, Lundberg, van Rentergem, Conolley, Bellinger, Slack, Stewart, and Hyde visited St Clair Cave in search of a very rare bat, Phyllonycteris aphylla. Explorations carried out at that time by McFarlane, van Rentergem, Christenson, Conolley, and Bellinger resulted in the discovery of a route through the breakdown boulders at the end of the Inferno that led into a continuing passage. Time constraints had prevented a full exploration of this new ground, but mapping was done from the farpoint back to a tie-in with the existing survey.

Om March 22, 2006, Stewart, Guy Van Rentergem, and Hilde Van Rentergem returned to continue the exploration of the continuing passage, which Guy had dubbed the Inferno+. The air in the Inferno, and Inferno+, was poor, but good enough that Stewart and G. Van Rentergem were able to carry on beyond the boulders for over 200m until a new passage with a flowing river was found, connected with the Inferno+ by a T-junction at the bottom of a steep, igneous-gravelled slope. The junction was low, and the air quality in the river passage was noticeably worse, which prevented further exploration. O2 sensors were not used, but by symptomatic camparison to later visits when sensors were used, Stewart estimates the O2 to have been under 15% (compared to the normal 21%), with an undetermined but high level of CO2 We surmised that the initial poor air from the Inferno onward was caused by a high BOD generated by copious amounts of bat guano in the water that sits on the floor of the Inferno (the location of the primary bat roost in St Clair, holding many thousands of bats), and also that the even poorer air in the Acheron was caused by a high BOD generated by input of sugar from Worthy Park Estate. The new river passage was named the Acheron by Van Rentergem to conform to the Inferno, both from Dante.

On June 3, 2006, Stewart, Pauel, and Andreas Haiduk visited St Clair Cave with sampling equipment to test the air in the Acheron passage, and a scuba tank to deal with the low O2. The air quality this time was very bad in the further reaches of the Inferno itself, estimated by Stewart to be under 14%, and we were not able to push through the boulders. We believed this to be because of a greater build-up of guano in the waters of the Inferno, and possible input from the Acheron, and Worthy Park.

In November of 2007, Haiduk, Pauel, and Stewart returned to the boulder breakdown at the end of the Inferno to more thoroughly flag the route (it can be difficult to locate), and found the air to be quite breathable, at about 18% O2.

On March 19, 2009, Garrez, Pauel, Stewart and Van Rentergem staged on all-out assault on the Acheron using rebreathers designed and built by Van Rentergem. He, and Garrez, managed to reach the river but O2 at 7.9% (and therefore CO2 at 13.1%) dissuaded them from being too adventurous, and the passage was only pushed about another 15m.

This brings us to November 3, 2012, and the visit described in the following notes.

Hyde, Pauel, and Stewart began the hike to the Polly Ground Entrance at about 11 AM. The flow in the Black River was moderate, <1m, causing the usual 30 minute hike along the dry riverbed to take somewhat longer, and the Inferno/Lemon Ridge junction wasn't reached until about 12:30.

Conditions in the Inferno were relatively good. The water pooled on the floor of the passage was fairly clear, the temperatures were lower than they can be, and the air, although obviously well under 21%, was not prohibitively poor. We made good time, and reached the boulders at the end of the Inferno within 20 minutes.

The route down through the boulders is not easily found, so on the previous visit we had flagged it well, and as a result we located it after only a minute or two of looking. The climb through/down was done, and we then began to refind the ongoing route. It took two tries, with us turning back to retrace things at one point. The route is such: At the bottom of the climb down, one goes though a vertical squeeze almost straight ahead. On the other side of this is shallow, pooled water. Here, one turns left and follows the water straight along the passage under large boulders. After about 20-30m, the boulder pile opens up overhead, and allows access up, and over the boulders to the left. You do not go that way (this is where we went astray on the first attempt). The ongoing route is straight ahead, under boulders, through a watery gap less than a metre high. From here, the route is obvious - it jogs to the left, then right (this is where Hilde waited for Guy and I during the discovery visit in 2006), and then after another 10m you reach the waiting point for the support team during the rebreather visit in 2009. In front of you now is a boulder barrier most easily passed by crawling under the righthand side of it. From this point on, you are in open passage.

The steep, igneous gravel/sand slope was soon reached, and we heard a tremendous roar of flowing water ahead of us. The air was still acceptable, so we slid down the slope, ducked under the stalactite covered opening that gives access to the Acheron passage, and beheld a river of very respectable proportions passing before us. It was quite impressive, and also very loud.

Pauel took up position on a pile of rocks in the middle of the river, straight ahead, to record video, while Hyde investigated upstream, and Stewart checked downstream.

Upstream, the river almost sumped, with less than 15cm of airspace below the ceiling. The depth was such that Hyde couldn't touch bottom. Further exploration would have to wait until the water level was lower.

Downstream, Stewart was able to go about 15m until the passage constricted, the water depth became over head-height, and the current was too strong to allow further progress. But by hanging onto the wall just beyond the constriction, another 10m+ of passage was seen angling about 30 degrees to the left. The ceiling gradually dropped from about 3m to 75cm, and at the low point there wasn't enough light to see much further. However, it did not appear to immediately sump.

The air was somewhat poorer in the Acheron than in the Inferno+. Stewart had to move rather slowly to keep his breathing rate down.

Partway up the gravel slope back up to the Inferno+, on the left wall, a sprouting seed was found that was too small to have been from bat foraging (it wasn't typical Artibeus food, and there are no A.j. in the Inferno+ to begin with). The vertical height above the flowing river was about 10m. Conditions are always moist enough on the slope that the seed would sprout soon after it was rafted in, so it had to have been deposited recently. We surmise that at some point in the previous several months, the river rose at least 10m, perhaps during Issac in late-August.

It can be seen from the above that the air quality, for the most part, is dependent on the time of the year of the visit. The worst period is after Worthy Park has been pressing for several months, and The Inferno has had a number of months of guano accumulation since the last flushing, which is March-April until July-September. The best period for exploration is October to January.

With regard to the source, and rising, for the Acheron: We believe the source to be somewhere in Worthy Park because of the correlation of air quality in the Acheron with pressing activity. It may be the Factory Sink, the Rio Cobre Sink, or somewhere else. We have no clear idea of where it rises. Tracing may establish it. A map that gives a GIS overview is included with this report.

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