These next two pictures do not come from our 1976-77 era, but I stumbled upon them on the NOAA web site
"For the context ... I wintered over during 1968 ... from early December 1967 until late December 1968...
"The two pictures in question show the main generator building. Number 1466 [below right] is the main generator building and number 1467 [above left] is looking down the "builder's tunnel" from outside, with the main generator building on the [left] and the head on the right. The generator building was seriously collapsing during w/o 1967 and a construction crew came in during December 1967, January 1968 to rebuild and shore up the building prior to w/o 1968. A large area of tunnels/buildings is uncovered for the construction. An unfortunate coincidence is that shortly after the construction, in early February 1968, one of the generators lost it's governor, and went into instant self destruct mode. I have a chunk of piston from that episode sitting on a bookcase at home. That piece of piston wedged itself into one of the new overhead timbers and forced some hasty re-construction. Other pieces of shrapnel, ex pistons, rods, bearings, etc, were found in other unlikely locations."
On this web site I've tried to adjust the colors and improve the focus a bit while shrinking the file size. Here is a direct link to the original of the above photo view from the NOAA site, plus a link to an 862k HUGE photo. Where's the builder's tunnel? Here's another link to the map which is not to scale. By the way, since 1968 the main power plant was moved at least one more time, to the location shown on my map. In 1977 that structure was drifted/iced in and inaccessible. We were able to get to the backup generator which was in a different tunnel. In the 90's Kim Stanley Robinson wrote about it ["Antarctica"], so he found it too...
One end of the seismo tunnel in 1977. I've seen pictures of this from 1973 and from the late 1990's and the view doesn't seem to have changed much. We did have to do some serious crawling to get to the seismo vaults and nonmagnetic huts at the far end, where we recovered some nonferrous heating fixtures for Alex's geomagnetic hut.
The main danger to human life in these tunnels (other than the cold) is NOT the risk of sudden collapse of the snow and ice above your head. Rather it is the fact that the uneven loads from this overburden has been slowly overstressing the construction materials (wood and steel) over the years, so that a brush with your mitten might be the final few ounces needed for a structural member to yield, or for an arch rivet to break loose like a bullet (some arch rivets were missing, and pieces of them could be found on the arch floors).
From my observations and readings, the snow cover over this station is not increasing and may even be decreasing due to wind action, since there is little surface disturbance, and some of the surface structures (aurora tower (skylab), rawin tower, BIT etc., have been removed,