A comparison between dinosaur footprints from the Middle Jurassic of the Isle of Skye, Scotland, UK, and Shell, Wyoming, USA

Measurements of Middle Jurassic tridactyl dinosaur tracks from the Bathonian, Lealt Shale, Valtos Sandstone, Duntulm and Kilmaluag formations of the Isle of Skye, UK, are compared to the same measurements taken for dinosaur footprints from the Bajocian, Gypsum Spring and the Bathonian, Sundance Formation of the Bighorn Basin, Wyoming, USA. Principal component analysis of the data suggests that the smaller footprints from the Valtos Sandstone and Kilmaluag formations are indistinguishable from the footprints of the Sundance Formation. The single footprint from the Lealt Shale Formation is similar to the larger footprints from the Valtos Sandstone Formation. The footprints from the Duntulm and Gypsum Springs formations form distinct groupings from all other footprints. Four different groupings of dinosaur footprints can be recognized from the principal component analysis that may represent at least four different types of dinosaur

Sensitivity of Pagurus bernhardus (L.) to substrate-borne vibration and anthropogenic noise

© 2015 Elsevier B.V. Despite the prevalence of vibration produced by anthropogenic activities impacting the seabed there are few data and little information as to whether these are detected by crustaceans and whether they interfere with their behaviour. Here the sensitivity of unconditioned Pagurus bernhardus to substrate-borne vibration was quantified by exposure to sinusoidal vibrations of 5-410Hz of varied amplitudes using the staircase method of threshold determination, with threshold representing the detection of the response and two behavioural responses used as reception indicators: movement of the second antenna and onset or cessation of locomotion. Thresholds were compared to measured vibrations close to anthropogenic operations and to the time in captivity prior to tests. Behaviour varied according to the strength of the stimulus with a significant difference in average threshold values between the two behavioural indicators, although there was an overlap between the two, with overall sensitivity ranging from 0.09-0.44ms -2 (root mean squared, RMS). Crabs of shortest duration in captivity prior to tests had significantly greater sensitivity to vibration, down to 0.02ms -2 (RMS). The sensitivity of P. bernhardus fell well within the range of vibrations measured near anthropogenic operations. The data indicate that anthropogenic substrate-borne vibrations have a clear effect on the behaviour of a common marine crustacean. The study emphasises that these vibrations are an important component of noise pollution that requires further attention to understand the long term effects on marine crustaceans

Sensitivity of the mussel Mytilus edulis to substrate‑borne vibration in relation to anthropogenically generated noise

© 2015 Inter-Research. Many anthropogenic activities in the oceans involve direct contact with the seabed (for example pile driving), creating radiating particle motion waves. However, the consequences of these waveforms to marine organisms are largely unknown and there is little information on the ability of invertebrates to detect vibration, or indeed the acoustic component of the signal. We quantified sensitivity of the marine bivalve Mytilus edulis to substrate-borne vibration by exposure to vibration under controlled conditions. Sinusoidal excitation by tonal signals at frequencies within the range 5 to 410 Hz was applied during the tests, using the 'staircase' method of threshold determination. Thresholds were related to mussel size and to seabed vibration data produced by anthropogenic activities. Clear behavioural changes were observed in response to the vibration stimulus. Thresholds ranged from 0.06 to 0.55 m s -2 (acceleration, root mean squared), with valve closure used as the behavioural indicator of reception and response. Thresholds were shown to be within the range of vibrations measured in the vicinity of anthropogenic operations such as pile driving and blasting. The responses show that vibration is likely to impact the overall fitness of both individuals and mussel beds of M. edulis due to disruption of natural valve periodicity, which may have ecosystem and commercial implications. The observed data provide a valuable first step to understanding the impacts of such vibration upon a key coastal and estuarine invertebrate which lives near industrial and construction activity, and illustrate that the role of seabed vibration should not be underestimated when assessing the impacts of noise pollution

CAVE DETECTION USING SEISMIC METHODS AT MADISON BLUE SPRING STATE PARK, MADISON COUNTY, FLORIDA

Locating caves and quantifying their geometries has significant importance in aquifer characterization, sinkhole mitigation, and contaminant transport monitoring. Several geophysical methods have been used for cave detection with limited success, but no reliable solution has been found. New developments in seismic techniques, however, show promising results indicating that cave voids may be more accurately detected. We evaluated the capability of several seismic techniques to detect caves by collecting new seismic data over a known conduit connected to Madison Blue Spring, in northern Florida. These analyses validated the abilities of diffracted surface waves to detect water-filled caves by viewing these data in the time and frequency domain. We also used refracted and reflected P-waves to model multiple incident reflections for the conduit roof. Delay times in the refracted wave were present at the conduit offset but depth calculations using these delays proved unsuccessful. We were, however, able to demonstrate that surface wave diffractions can be synthetically modeled to verify field results. The combination of these seismic techniques was ultimately successful in determining the location, depth and approximate diameter of the conduit at Madison Blue Spring

The impact of climate change on phytoplankton - bacterioplankton interactions

Global warming has already and is continuing to impact the global oceans. Half of the global primary production is performed by phytoplankton in the oceans and heterotrophic marine bacteria channel a substantial amount of primary organic carbon through the microbial loop. Understanding the influence of climate change on these important processes is therefore essential for an assessment of the vulnerability of the carbon cycle and possible feedbacks. This thesis reports results from investigations on the temperature dependent coupling between phytoplankton and bacterioplankton, with respect to additional effects of light intensity and inorganic nutrient concentrations. During four consecutive years, mesocosm experiments with natural Kiel Fjord winter plankton communities investigated the influences of increasing water temperatures of up to ΔT +6°C and different light intensities between 16 and 100% of natural incident light. In an additional microcosm experiment with a single algal species and the natural bacterial community, two inorganic nutrient concentrations were used, in order to evaluate the combined effects of temperature and substrate on the algal-bacterial coupling. Summarising the results from all experiments it can be concluded, that increasing temperatures generally led to an increased heterotrophic bacterial organic substrate utilisation relative to primary production. In combination with a further brightening, the supplemental promotion of primary production would increase the absolute amounts of cycled organic matter. Future increasing P-limitation in coastal waters would lead not only to an enhanced absolute amount of cycled carbon, but additionally to an increased relative amount of remineralised organic carbon through the microbial loop. An enhanced organic matter transfer through the microbial loop has the potential to alter the whole structure and functioning of the marine food web and the biological sequestration of carbon to depth. Additionally, a substantial rise of CO2 emissions through enhanced respiration represents a positive feedback loop to the global climate change problem

A study of the preachment and practice of the Reverend Mr. Oral Roberts

https://place.asburyseminary.edu/ecommonsatsdissertations/2188/thumbnail.jp