|
Goatchurch Cavern
Goatchurch Cavern is a cave on the edge of Burrington Combe in the limestone of the Mendip Hills, in Somerset, England. Description Due to early attempts to turn it into a show cave, there are remains of iron handrails inside the cave and a large amount of decoration throughout the cave. Many of the surfaces within are highly polished and slippery, as a result of numbers visiting over many decades, which have also damaged the decoration. The cave is especially popular for training people who are new to caving. This is due to its easy access and wide range of experiences that do not necessitate the use of special equipment such as ropes or ladders. The two entrances to the cave enable cavers to do a through trip. History The earliest written record of this cave was in 1736 when John Strachey of Sutton Court at nearby Stowey made reference to "guy Hole" or "Goechurch". In 1829 John Rutter wrote about the large cave and in 1864 William Boyd Dawkins referred to it as "The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burrington Combe
Burrington Combe is a Carboniferous Limestone gorge near the village of Burrington, on the north side of the Mendip Hills Area of Outstanding Natural Beauty, in North Somerset, England. "Combe" or "coombe" is a word of Celtic origin found in several forms on all of the British Isles, denoting a steep-sided valley or hollow. Burrington Combe is a gorge through the limestone hills although there is now no river running through it. Various cave entrances are exposed which have been occupied by humans for over 10,000 years, with a hillfort being built beside the combe in the Iron Age. The geology has led to a diversity of plant life. According to legend Augustus Montague Toplady was inspired to write the hymn ''Rock of Ages'' while sheltering under a rock in the combe, although recent scholars have disputed this claim. Geology Water draining from Black Down has exposed rocks from the Devonian sandstones of the Portishead Formation which show through the limestone, Carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caves Of The Mendip Hills
The caves of the Mendip Hills are formed by the particular geology of the Mendip Hills: large areas of limestone worn away by water makes it a national centre for caving. The hills conceal the largest underground river system in Britain. Geology The hills consist of anticlines of Carboniferous Limestone lying over Devonian Old Red Sandstone, with the sandstone exposed on the summits. When a surface stream running off the sandstone reaches the limestone it sinks below ground through a " swallet", (also known locally as a "slocker"), continuing on its way down towards sea level by enlarging existing cracks in the rock to form caves, and reappearing at the base of the limestone outcrop. As the water changes route within the hill some caves (or parts of caves) are left dry. There is a characteristic type of Mendip cave, in which there is an initially steep descent, and then a more level stretch ending in a "sump" as the cave reaches and descends below the prevailing water table. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sievert
The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radiation, which is defined as the probability of causing radiation-induced cancer and genetic damage. The sievert is important in dosimetry and radiation protection. It is named after Rolf Maximilian Sievert, a Swedish medical physicist renowned for work on radiation dose measurement and research into the biological effects of radiation. The sievert is used for radiation dose quantities such as equivalent dose and effective dose (radiation), effective dose, which represent the risk of external radiation from sources outside the body, and committed dose, which represents the risk of internal irradiation due to inhaled or ingested radioactive substances. According to the International Commission on Radiological Protection (ICRP) one sievert r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ) * ''particle radiation'', such as alpha radiation (α), beta radiation (β), proton radiation and neutron radiation (particles of non-zero rest energy) * '' acoustic radiation'', such as ultrasound, sound, and seismic waves (dependent on a physical transmission medium) * ''gravitational wave, gravitational radiation'', that takes the form of gravitational waves, or ripples in the curvature of spacetime Radiation is often categorized as either ''ionizing radiation, ionizing'' or ''non-ionizing radiation, non-ionizing'' depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volt, eV, which is enough to ionize atoms and molecules and break ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radon
Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colourless, odourless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through which thorium and uranium slowly decay into various short-lived radioactive elements and lead. Radon itself is the immediate decay product of radium. Its most stable isotope, 222Rn, has a half-life of only 3.8 days, making it one of the rarest elements. Since thorium and uranium are two of the most common radioactive elements on Earth, while also having three isotopes with half-lives on the order of several billion years, radon will be present on Earth long into the future despite its short half-life. The decay of radon produces many other short-lived nuclides, known as "radon daughters", ending at stable isotopes of lead. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caver
Caving – also known as spelunking in the United States and Canada and potholing in the United Kingdom and Ireland – is the recreational pastime of exploring wild cave systems (as distinguished from show caves). In contrast, speleology is the scientific study of caves and the cave environment.Caving in New Zealand (from Te Ara: The Encyclopedia of New Zealand, Accessed 2012-11.) The challenges involved in caving vary according to the cave being visited; in addition to the total absence of light beyond the entrance, negotiating pitches, squeezes, [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boulder
In geology, a boulder (or rarely bowlder) is a rock fragment with size greater than in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In common usage, a boulder is too large for a person to move. Smaller boulders are usually just called rocks or stones. The word ''boulder'' derives from ''boulder stone'', from the Middle English ''bulderston'' or Swedish ''bullersten''. Online Etymology Dictionary. Retrieved December 9, 2011, from Dictionary.com website. In places covered by s during s, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phreatic
''Phreatic'' is a term used in hydrology to refer to aquifers, in speleology to refer to cave passages, and in volcanology to refer to a type of volcanic eruption. Hydrology The term phreatic (the word originates from the Greek , meaning "well" or "spring") is used in hydrology and the earth sciences to refer to matters relating to ground water (an aquifer) below the water table. The term 'phreatic surface' indicates the location where the pore water pressure is under atmospheric conditions (i.e. the pressure head is zero). This surface normally coincides with the water table. The slope of the phreatic surface is assumed to indicate the direction of ground water movement in an unconfined aquifer. The phreatic zone, below the phreatic surface where rock and soil is saturated with water, is the counterpart of the vadose zone, or unsaturated zone, above. Unconfined aquifers are also referred to as phreatic aquifers because their upper boundary is provided by the phreatic surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Bristol Spelæological Society
The University of Bristol Spelæological Society (UBSS) was founded in 1919 by cavers in the University of Bristol. Among its earliest activities was the archaeological excavation of Aveline's Hole. The club owns a hut, which was formerly a ladies' cricket pavilion. It was bought in 1919 for £5 and moved from its original plot to Burrington Combe, where it still stands. Publications and library The club maintains one of the largest collections of caving books and journals in the country in its library in Bristol, as well as publishing the long-standing academic journal, ''Proceedings of the University of Bristol Spelæological Society''. Following numerous expeditions to the Burren, County Clare over the years, the UBSS has published the definitive guides to the caves of the region: ''Caves of Northwest Clare'' (1969), ''Caves of County Clare'' (1981), ''Caves of County Clare & South Galway'' (2003), ''Caves of Mid-West Ireland'' (2019) and ''Caves of southern Ireland'' (2022). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Witches' Mark
A witch's mark or devil's mark was a bodily mark that witch-hunters believed indicated that an individual was a witch, during the height of the witch trials. The beliefs about the mark differ depending on the trial location and the accusation made against the witch. Evidence of the witch's mark is found earliest in the 16th century, and reached its peak in 1645, then essentially disappeared by 1700. The Witch or Devil's mark was believed to be the permanent marking of the Devil on his initiates to seal their obedience and service to him. He created the mark by raking his claw across their flesh, or by making a blue or red brand using a hot iron. Sometimes, the mark was believed to have been left by the Devil licking the individual leaving a death skull pattern in the skin. The Devil was thought to mark the individual at the end of nocturnal initiation rites. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patina
Patina ( or ) is a thin layer that variously forms on the surface of copper, brass, bronze and similar metals and metal alloys (tarnish produced by oxidation or other chemical processes) or certain stones and wooden furniture (sheen produced by age, wear, and polishing), or any similar acquired change of a surface through age and exposure. Additionally, the term is used to describe the aging of high-quality leather. The patinas on leather goods are unique to the type of leather, frequency of use, and exposure. Patinas can provide a protective covering to materials that would otherwise be damaged by corrosion or weathering. They may also be aesthetically appealing. Usage On metal, patina is a coating of various chemical compounds such as oxides, carbonates, sulfides, or sulfates formed on the surface during exposure to atmospheric elements (oxygen, rain, acid rain, carbon dioxide, sulfur-bearing compounds). In common parlance, weathering rust on steel is often mistakenly refe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Witches' Mark")
