USGS ScienceSearch

Geology topics

Research about Mammoth Cave National Park

Source-linked reports with geographic coverage including Mammoth Cave National Park.

3 recordsLinked to original sources

Vibration monitoring results near a bat hibernaculum at Mammoth Cave National Park, Kentucky, March 2016

Vibrations originating from construction of a new walkway in a passage of Mammoth Cave, from walking personnel simulating a bat survey, and from ambient sources were measured near a bat hibernaculum beneath Mammoth Cave National Park, Kentucky, to determine if the vibrations were disturbing the hibernating bats. Data presented indicate direction and magnitude of the vibrations. The seven sources of vibration that were recorded include hammer drill (one location), plate compactor (two locations), jackhammer (two locations), personnel simulating a bat survey near the hibernaculum (walking throughout the cave), and background levels. Vibrations were measured for approximately 10 seconds during each triggering of the source and each source was recorded 5–10 times to represent the reproducibility of the vibrations. The plate compactor produced the largest velocity of 0.00226 inch per second on one of the longitudinal components. The simulated bat survey produced the largest value of acceleration of 0.34 inch per square second in the vertical component. Maximum vertical velocities and accelerations did not exceed literature values for human perception or visible agitation in laboratory mice.

Kentucky

Consumption of freshwater bivalves by muskrats in the Green River, Kentucky

Muskrats (Ondatra zibethicus) are known to prey on freshwater bivalves (mussels and clams) and can negatively impact imperiled mussel species. However, factors that influence muskrat predation on bivalves are poorly understood. We evaluated the feeding ecology of muskrats in the Green River, Kentucky, by using stable isotope analysis of muskrat hair samples and by monitoring bivalve shell deposition at muskrat middens. Bayesian mixing-model analysis of stable isotope δ 15 N and δ 13 C ratios revealed that the median muskrat biomass derived from bivalves was 51.4% (5th and 95th percentiles were 39.1 to 63.4%, respectively), a much higher dietary proportion than previously reported. Shell depositions by muskrats at middens decreased with the availability of seasonal emergent vegetation, suggesting that the consumption of animal matter is in response to a scarcity of plant foods, perhaps exacerbated by the altered flow regimes on the Green River. Our results add to the growing body of evidence that muskrats have the potential to impact mussel population growth and recovery in some environments.

Kentucky

Some engineering geology problems at Mammoth Cave National Park, Kentucky

The U.S. Geological Survey, at the request of the rational Park Service, participated in a field symposium May 22-26, 1967, at Mammoth Cave National Park, Kentucky. This symposium, held by the National Park Service, was to determine the applicability of the Wilderness Act of 1964 to underground and surface portions of the Park (W. Drew Chick, Jr., written communication, 1967). Scientific evidence bearing on the relationships between human surface activities and natural underground openings was examined and discussed at the symposium. This report discusses relations between various types of surface activities and physical damage to the cave openings and features. Additional interpretive material is taken from the literature and from limited laboratory information. Possible hydrologic and biologic effects are not considered here, but were investigated by other members of the symposium. Hydrologic effects are discussed in companion report by Robert V. Cushman of the Geological Survey.

Kentucky