Cover-collapse sinkholes in Kentucky, USA: geographic and temporal distribution
| Autor: | James C. Currens |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | Carbonates and Evaporites. 27:137-142 |
| ISSN: | 1878-5212 0891-2556 |
| DOI: | 10.1007/s13146-012-0097-2 |
| Popis: | Sudden and unpredictable collapse of unconsolidated cover over soluble bedrock defines cover collapse. Cover collapse in Kentucky frequently damages buildings, roads, utility lines, and farm equipment. It has killed livestock, including thoroughbred horses, and has injured people at an estimated annual cost of $20 million. The Kentucky Geological Survey began developing a file of case histories of cover collapse in 1997 and now receives approximately 24 reports annually. The case history file contains 247 individual entries and spans some 30 years, yet is thought to represent only a fraction of the annual occurrences. The reported sites are distributed statewide but are concentrated in urban settings. The largest cover collapse recorded was in Logan County and was 15.5 m in diameter and 18 m deep. The Dishman Lane collapse in Bowling Green, KY, although larger, included some bedrock collapse. Collapse features have an average long axis length of 3.1 m and an average observable depth of 2.6 m. The ratio of the long and short axes of the collapse at ground level is 1.30. When plotted on a digitized topographic overlay showing outlines of mapped sinkholes, 11 % of the cover-collapse sites are inside a mapped sinkhole. Of a total of 124 observations that noted the presence or absence of buried trash, 10.7 % of sinkholes had trash present. Nearly 52 % of collapses are underlain by Mississippian rocks, whereas 39.7 % are underlain by Ordovician carbonates. The remaining percentage is underlain by Silurian and Devonian carbonates or lithology is undetermined. The most common months for cover collapse are April, May, and June. Continued accumulation of case histories of cover collapse in Kentucky will result in a better understanding of where, when, how, and why cover collapse occurs. |
| Databáze: | OpenAIRE |
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