ANWR's Index Approximate number of miles of these scars that are still visible in the check out these pictures: photo1 photo2 photo3 photo4 "There are 100 plots from which we get much of the detailed data on tundra disturbance, but are not a random sample of points on the trails. They were subjectively chosen to include multiple plots in all major vegetation types, at all different levels of disturbance. The purpose was to compare disturbance and recovery in the different vegetation types, different trail types, and different levels of initial disturbance. We cannot imply that they tell what percentage of points on all trails are still disturbed. To do that, we visited a different set of 200 randomly selected points. Here is the correct data from both sets of plots: ~100 subjectively located plots: 1998: 49% still showing some disturbance. 200 randomly selected plots: 1998: 7% still showing some disturbance. (Translates to about 260 km of the original 4000 km of trails.) No complete data set on aerial visibility exists, but based on a partial data set we know the number still visible from the air is greater than the number still rated as disturbed on the ground. A good estimate is about 15 - 20% by 1998. Attached document (in PDF format here) is a recent summary of the seismic trail study and conclusions. I've also attached a few photographs of trails taken June 30, 2000." read more... sources: -Janet Jorgenson, USFWS biologist who does the seismic trail monitoring. -Cathy Curby, Arctic National Wildlife Refuge. return to index return to index