12 research outputs found
Limestone quarries and cave protection
It happened in Hungary several times that a limestone quarry opened the entrance of a new, unknown cave during its activity such as the case was in the VillĂĄny Mountains, in Budapest, and in Kesel?, NaszĂĄly or Esztramos Hills. It is right that the natural caves are protected, but what is the solution in such cases? Closing the mine? Absolving the cave from protection? It is a difficult question. The real way: we must weigh. Which is more expensive? How valuable and unique is the cave? How big is the economic loss if we close the mine? And how serious is the harm if it is allowed to annihilate the value of nature, which is impossible to reproduce? Examples follow from Hungary
Conceptualization and implementation of a groundwater flow model for the Buda thermal-karst system, Hungary
Risk factors of migraine-related brain white matter hyperintensities: an investigation of 186 patients
Brain white matter hyperintensities are more prevalent in migraine patients than in the general population, but the pathogenesis and the risk factors of these hyperintensities are not fully elucidated. The authors analyzed the routine clinical data of 186 migraine patients who were referred to the Outpatient Headache Department of the Department of Neurology, Medical School, University of Pécs, Hungary between 2007 and 2009: 58 patients with white matter hyperintensities and 128 patients without white matter hyperintensities on 3 T MRI. Significant associations between the presence of white matter hyperintensities and longer disease duration (14.4 vs. 19.9 years, p = 0.004), higher headache frequency (4.1 vs. 5.5 attacks/month, p = 0.017), hyperhomocysteinemia (incidence of hyperintensity is 9/9 = 100%, p = 0.009) and thyroid gland dysfunction (incidence of hyperintensity is 8/14 = 57.1%, p = 0.038) were found. These data support the theory that both the disease duration and the attack frequency have a key role in the formation of migraine-related brain white matter hyperintensities, but the effects of comorbid diseases may also contribute to the development of the hyperintensities
Hydraulic evaluation of the hypogenic karst area in Budapest (Hungary)
The Buda Thermal Karst area, in central Hungary, is in the focus of research interest because of its thermal water resources and the on-going hypogenic karstification processes at the boundary of unconfined and confined carbonates. Understanding of the discharge phenomena and the karstification processes requires clarification of the groundwater flow conditions in the area. Consequently, the aim of the present study was to present a hydraulic evaluation of the flow systems based on analyzes of the archival measured hydraulic data of wells. Pressure vs. elevation profiles, tomographic fluid-potential maps and hydraulic cross sections were constructed, based on the data distribution. As a result, gravitational flow systems, hydraulic continuity, and the modifying effects of aquitard units and faults were identified in the karst area. The location of natural discharge areas could be explained and the hydraulic behavior of the Northeastern Margin Fault of the Buda Hills could be determined. The flow pattern determines the differences in the discharge distribution (one- and two-component) and related cave-forming processes between the Central System (Rózsadomb area) and Southern System (Gellért Hill area) natural discharge areas. Among the premises of hypogenic karstification, regional upward flow conditions were confirmed along the main discharge zone of the River Danube. The flow pattern determines the differences in the discharge distribution (one- and two-component) and related cave-forming processes between the Central System (Rózsadomb area) and Southern System (Gellért Hill area) natural discharge areas. Among the premises of hypogenic karstification, regional upward flow conditions were confirmed along the main discharge zone of the River Danube. The flow pattern determines the differences in the discharge distribution (one- and two-component) and related cave-forming processes between the Central System (Rózsadomb area) and Southern System (Gellért Hill area) natural discharge areas. Among the premises of hy
Hypogene Caves of the Tasmanic Karsts of Eastern Mainland Australia
The Tasmanic karsts of eastern Australia extend from the south-eastern tip of Tasmania to the far north of Queensland. The mainland section incorporating the eastern parts of Victoria, New South Wales and Queensland contains more than one hundred and twenty bodies of cavernous Palaeozoic limestone, most of which form impounded karsts. Many of these karst areas are small, difficult to access, contain a small number of caves and have received little attention from cavers and even less attention from scientists. Some 21 karst areas stand out for their number of caves and their diversity of underground features. Almost all of the Tasmanic caves in mainland Australia show a high degree of structural guidance and are developed in massive high-purity limestone. Solution dolines are rare or absent in the surrounding karst. Some caves appear to have been formed entirely by a single hypogenic event while others have been modified by several hypogenic events (multiphase caves). In other caves, hypogene forms have been overprinted by later epiphreatic, paragenetic, fluvial and breakdown events (multiphase/multiprocess caves). Where there are active rivers in the caves, the rivers are often much smaller than the cavities they flow through, take complex paths through the rock and are captured into pre-existing cavities. The evidence for a hypogene origin of these caves is largely morphological, but is supported by circumstantial evidence such as intersection of palaeokarst, proximity to regional faults and tenuous relationships with the surrounding geomorphology and hydrology