Perennial Snow and Ice Changes in the Crazy Mountains, Montana from 1972 to 2020: A Model for Ice Patch Archaeology Exploration

Keywords: Water resources, perennial snow and ice, Rocky Mountains, Montana, Crazy Mountains
Abstract Type: Paper Abstract

Abstract

As climate changes and temperatures rise across the globe, perennial snow and ice patches are melting and disappearing in alpine areas. These potential archaeological sites are being immensely affected and, in some cases, destroyed. This research was conducted to determine if remote sensing imagery could detect the extent of perennial snow/ice patch loss and determine the ice patches most vulnerable to melting in the Crazy Mountains of Montana. United State Geological Survey and National Agriculture Inventory Program imagery was used to identify and digitize perennial snow/ice patches over the range of years 1972, 1998, 2005, 2011, and 2020. Suitability models were developed in ArcGIS Pro using the variables elevation, aspect, slope, distance to pathways, incoming solar radiation, and aerial extent of ice and snow patches, to identify those most vulnerable to melting and likely to hold archaeological or biological artifacts. Fuzzy membership and weighted suitability methods were used to develop these models. Fifty-seven perennial snow/ice patches were identified and digitized from 1972 data, with 52 visible in 2020 imagery. Aerial extent of these ice patches was greatest in 1998, and 2005 had the least extent including patches that had disappeared. The weighted overlay suitability model identified 19 snow/ice patches most favorable for melting and containing artifacts, while the overlay suitability model identified 46. This research showed that remote sensing applications such as suitability models and imagery can be effective in determining perennial snow/ice patches that are more at risk of melting and likely to risk of melting sooner than later.