KEENE VALLEY - State glacial geologist Andrew Kozlowski and his assistant, geologist Brian Bird, were back in town Monday, July 9, with some good news: The land slide in Keene Valley's Adrian's Acres subdivision was not accelerated by Tropical Storm Irene, which struck August 28.
In fact, since July, 2011, the slide has slowed dramatically, with little movement at the crown, or top, of the slide.
Kozlowski is senior scientist at the New York State Geologic Survey/New York State Museum, a branch of the State Education Department. His job has both academic and service aspects, including conducting research for the public benefit, geological mapping, glacial geology and troubleshooting hazards.
Martha Allen/Lake Placid News
State glacial geologist Andrew Kozlowski at the landslide area in Keene Valley on July 9.
On Monday, Kozlowski and Bird were leading 22 earth science teachers from schools in Potsdam to Long Island on a tour of the slide "to see geology in action," as Kozlowski put it.
"I want students to learn we live on an active, dynamic planet," he said.
Bird demonstrated the Stevens Type F Recorder, or creep meter, as he and Kozlowski have nicknamed it. This device, connected by a cable to a tree 15 feet lower down on the slope of Bobcat Basin, accurately graphs hillside creep over time. By looking at the inked lines on the paper graph, scientists can see when and how much the earth has moved. The creep meter is sensitive. Wind events powerful enough to shake the tree and even animal visits-birds sitting on the device, for example- are also recorded. The meter is checked twice a month.
The bottom, or toe, of the slide is still active, moving at the rate of two inches a month. At this time it is threatening a hunting camp, but no homes.
"The hillside may reach equilibrium," Kozlowski said. "There is a chance it may stabilize."
In 2011, melting of the snow pack combined with intense rain starting in April added to the groundwater, causing a failure, or slide, he explained. Last winter we had little snow and the summer has been dry. If this pattern of low precipitation continues, the sliding action may subside.
The Merle-Smith, Marlatt, Machold, Hopkins and Grinker properties on the top of the slide have all been affected. The Marlatts have moved their house to a less perilous location, the Macholds have torn down and buried their torqued and broken house, and the Grinkers' former residence perches on the brink of the scarp, a staircase hanging uselessly over the edge. The Merle-Smith house was built on bedrock, but their back yard has fallen away precipitously.
"There are still homes in concern," Kozlowski told the group. "It is inevitable they'll get caught on the edge of the scarp and fail."
While Kozlowski was in the woods taking measurements last May, "Large trees were falling with an uncomfortable regularity, " and "Boulders were beginning to loosen and roll. One boulder rolled right past me."
On the peripheries of the slide, trees were twisted, uprooted or split, but in the heart of the slide "they were just coasting," he said. At the crown, movement has been more vertical than lateral, with shearing action. Earth at the toe can move "like a Slinky."
How does this slide compare with others?
While on a nationwide scale it is considered moderate, it is large for the North East. In New York, the Keene Valley slide, at 82 acres, .8 miles in overall length, is unprecedented in scale. It is the largest in the state's history. New York has many small slides, which often go unreported. Two acres is ot uncommon.
This kind of earth movement is a juggernaut, he said, a relentlessly crushing force which, compared to a debris slide, is relatively slow. After Irene, debris slides happened within hours. There is no way to predict when the Adrian's Acres land slide will stop moving. It could be months or many years.
Kozlowski has been in close touch with townspeople here since May 10, 2011. He has talked with people whose homes were in danger and to town officials, to reporters and to the student body at Keene Central School. Although powerless to reverse the movement of the slide, he and Bird have continued to educate the populace and provide some reassurance.