New Data and Techniques for Evaluating Subsidence from Abandoned Underground Mines in Ohio
Subsidence due to the collapse of abandoned underground mines is a geologic hazard that can affect buildings, highways, and infrastructure, potentially endangering lives and property. Further, damages from mine subsidence can cost millions of dollars. Between 2008 and 2011, the Ohio Department of Natural Resources (ODNR), Division of Mineral Resources Management invested more than $2.4 million to complete 87 projects related to abandoned underground mines. The costs of mine subsidence are expected to rise as abandoned underground mines age and deteriorate and as further development occurs across the Ohio landscape.
The ODNR Division of Geological Survey (the Survey) has been responsible for mapping the locations of abandoned underground mines since 1977. The mapping process involves creating and managing a GIS of abandoned underground mines in Ohio. A recently developed custom GIS application allows Survey staff geologists to quickly gather any geologic data on file at the Survey that is relevant to a subsidence complaint. Once the information has been gathered into the GIS, a geologist writes a report summarizing the data and noting critical information. The report is submitted to either the Division of Mineral Resources Management or a consulting engineering company assigned to the complaint for further evaluation, site inspection, and potential remediation. The GIS software application provides easy access to digital geologic information for evaluation and potential property remediation.
New datasets also are being developed as part of the ongoing mapping program. The Survey is the archive for all final abandonment mine maps, which are scanned at a high resolution and georeferenced to existing ground control. Using georeferenced mine maps, the elevation, thickness, and information on the condition of each mine is captured into the GIS. These datasets, in addition to new statewide LiDAR and other digital geologic datasets, are used to identify areas at high risk due to mine subsidence. Variables analyzed as part of this study include age of a mine, depth to a mine, amount of unconsolidated overburden, and roof rock lithology. The new datasets will provide a better understanding on the variables controlling mine subsidence from abandoned mines.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013