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107-578: Methana is situated on a volcanic (the Methana Volcano ) peninsula , attached to the Peloponnese. Administratively, it belongs to the Attica region. The town (pop. 892 in 2011) is located north of the road connecting to the rest of the Peloponnese and Galatas. The highest point is 740 metres (2,428 feet) (Helona Mountain). The municipal unit has a land area of 50.161 square kilometres (19.367 square miles) and

214-463: A Greek sculptural style , with attributes taken from Egyptian and Greek tradition. Some of these images reflected her linkage with other goddesses in novel ways. Isis-Thermuthis, a combination of Isis and Renenutet who represented agricultural fertility, was depicted in this style as a woman with the lower body of a snake. Figurines of a woman wearing an elaborate headdress and exposing her genitals may represent Isis-Aphrodite. The tyet symbol,

321-529: A ghost town ) and Fourpeaked Mountain in Alaska, which, before its September 2006 eruption, had not erupted since before 8000 BCE. Isis (goddess) Meroitic : Wos[a] or Wusa B C D F G H I K M N P Q R S T U W Isis was a major goddess in ancient Egyptian religion whose worship spread throughout the Greco-Roman world . Isis

428-476: A magma chamber below the surface. The process that forms volcanoes is called volcanism . On Earth, volcanoes are most often found where tectonic plates are diverging or converging , and because most of Earth's plate boundaries are underwater, most volcanoes are found underwater. For example, a mid-ocean ridge , such as the Mid-Atlantic Ridge , has volcanoes caused by divergent tectonic plates whereas

535-400: A sistrum rattle and a headdress of cow horns enclosing a sun disk. Sometimes both headdresses were combined, so the throne glyph sat atop the sun disk. In the same era, she began to wear the insignia of a human queen, such as a vulture-shaped crown on her head and the royal uraeus , or rearing cobra, on her brow. In Ptolemaic and Roman times, statues and figurines of Isis often showed her in

642-552: A cow—an origin myth explaining the cow-horn headdress that Isis wears. Isis's maternal aspect extended to other deities as well. The Coffin Texts from the Middle Kingdom ( c.  2055 –1650 BCE) say the Four sons of Horus , funerary deities who were thought to protect the internal organs of the deceased, were the offspring of Isis and the elder form of Horus. In the same era, Horus

749-454: A gesture of mourning, or outstretched around Osiris or the deceased as a sign of their protective role. In these circumstances they were often depicted as kites or women with the wings of kites. This form may be inspired by a similarity between the kites' calls and the cries of wailing women, or by a metaphor likening the kite's search for carrion to the goddesses' search for their dead brother. Isis sometimes appeared in other animal forms: as

856-437: A graduated spectrum, with much overlap between categories, and does not always fit neatly into only one of these three separate categories. The USGS defines a volcano as "erupting" whenever the ejection of magma from any point on the volcano is visible, including visible magma still contained within the walls of the summit crater. While there is no international consensus among volcanologists on how to define an active volcano,

963-530: A looped shape similar to the ankh , came to be seen as Isis's emblem at least as early as the New Kingdom, though it existed long before. It was often made of red jasper and likened to Isis's blood. Used as a funerary amulet , it was said to confer her protection on the wearer. Despite her significance in the Osiris myth, Isis was originally a minor deity in the ideology surrounding the living king. She played only

1070-515: A mother to the deceased, providing protection and nourishment. Thus, like Hathor, she sometimes took the form of Imentet , the goddess of the west, who welcomed the deceased soul into the afterlife as her child. But for much of Egyptian history, male deities such as Osiris were believed to provide the regenerative powers, including sexual potency, that were crucial for rebirth. Isis was thought to merely assist by stimulating this power. Feminine divine powers became more important in afterlife beliefs in

1177-443: A paper was published suggesting a new definition for the word 'volcano' that includes processes such as cryovolcanism . It suggested that a volcano be defined as 'an opening on a planet or moon's surface from which magma , as defined for that body, and/or magmatic gas is erupted.' This article mainly covers volcanoes on Earth. See § Volcanoes on other celestial bodies and cryovolcano for more information. The word volcano

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1284-529: A population of 1,352 inhabitants at the 2021 census. The municipal unit Methana is subdivided into the following communities (constituent villages in brackets): Half of the entire peninsula's population lives in Methana town. The peninsula is entirely of volcanic origin and contains over 30 volcanic eruption centers. The last volcanic eruption occurred near present-day Kameni Chora in 3rd century BC. Famous writers such as Ovid , Strabo and Pausanias reported

1391-470: A sign of her identity. The symbol serves as a phonogram , spelling the st sounds in her name, but it may have also represented a link with actual thrones. The Egyptian term for a throne was also st and may have shared a common etymology with Isis's name. Therefore, the Egyptologist Kurt Sethe suggested she was originally a personification of thrones. Henri Frankfort agreed, believing that

1498-426: A sign that Isis had the power to predict or influence future events, as did other deities who presided over birth, such as Shai and Renenutet . Texts from much later times call Isis "mistress of life, ruler of fate and destiny" and indicate she has control over Shai and Renenutet, just as other great deities such as Amun were said to do in earlier eras of Egyptian history. By governing these deities, Isis determined

1605-598: A small role, for instance, in the Dramatic Ramesseum Papyrus , the script for royal rituals performed in the reign of Senusret I in the Middle Kingdom. Her importance grew during the New Kingdom, when she was increasingly connected with Hathor and the human queen. The early first millennium BCE saw an increased emphasis on the family triad of Osiris, Isis, and Horus and an explosive growth in Isis's popularity. In

1712-400: A smaller one and the mountains of the eastern tip of the neighboring peninsula. Much of the peninsula is mountainous and bushy and grassy. The mountain range covers the central part of the peninsula and has a small ridge north of the seat. The residential area is within the sea. The pastures are around Methana. A mountain ridge is founded in the west and is about 3 km (2 mi) long with

1819-415: A sow, representing her maternal character; as a cow , particularly when linked with Apis; or as a scorpion. She also took the form of a tree or a woman emerging from a tree, sometimes offering food and water to deceased souls. This form alluded to the maternal nourishment she provided. Beginning in the New Kingdom, thanks to the close links between Isis and Hathor, Isis took on Hathor's attributes, such as

1926-559: A stream in the middle and a cliff in the south. The earliest known settlement (near the village of Vathy) dates from 1500–1300 BC. The first survey was conducted by Michael Deffner , who discovered a large throne , among other artefacts. Many ancient sites were identified through the archaeological survey conducted in the 1980s by the University of Liverpool in association with the British School at Athens. The Acropolis Palaiokastro

2033-567: A topographical map of the entire peninsula at a scale of 1:25,000 was made. An interactive 3D map was created and is on the World Wide Web. Also a rich photographic archive with about 10.000 color slides has been produced (see links below). The panorama of the northeastern part of Argolis , southeastern and eastern Corinthia along with the southern part of the Attica peninsula and the Saronic Islands of Aegina and Salamis along with

2140-632: A volcano is largely determined by the composition of the lava it erupts. The viscosity (how fluid the lava is) and the amount of dissolved gas are the most important characteristics of magma, and both are largely determined by the amount of silica in the magma. Magma rich in silica is much more viscous than silica-poor magma, and silica-rich magma also tends to contain more dissolved gases. Lava can be broadly classified into four different compositions: Mafic lava flows show two varieties of surface texture: ʻAʻa (pronounced [ˈʔaʔa] ) and pāhoehoe ( [paːˈho.eˈho.e] ), both Hawaiian words. ʻAʻa

2247-555: A volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit; however, this describes just one of the many types of volcano. The features of volcanoes are varied. The structure and behaviour of volcanoes depend on several factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have landscape features such as massive plateaus . Vents that issue volcanic material (including lava and ash ) and gases (mainly steam and magmatic gases) can develop anywhere on

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2354-465: A volcano that has experienced one or more eruptions that produced over 1,000 cubic kilometres (240 cu mi) of volcanic deposits in a single explosive event. Such eruptions occur when a very large magma chamber full of gas-rich, silicic magma is emptied in a catastrophic caldera -forming eruption. Ash flow tuffs emplaced by such eruptions are the only volcanic product with volumes rivalling those of flood basalts . Supervolcano eruptions, while

2461-494: A wealthy woman who has refused to help Isis by stinging the woman's son, making it necessary for the goddess to heal the blameless child. Isis's reputation as a compassionate deity, willing to relieve human suffering, contributed greatly to her appeal. Isis continues to assist her son when he challenges Set to claim the kingship that Set has usurped, although mother and son are sometimes portrayed in conflict, as when Horus beheads Isis and she replaces her original head with that of

2568-490: Is Osiris's wife as well as his sister , is his queen. Set kills Osiris and, in several versions of the story, dismembers his corpse. Isis and Nephthys, along with other deities such as Anubis , search for the pieces of their brother's body and reassemble it. Their efforts are the mythic prototype for mummification and other ancient Egyptian funerary practices . According to some texts, they must also protect Osiris's body from further desecration by Set or his servants. Isis

2675-727: Is a volcanic field of over 60 cinder cones. Based on satellite images, it has been suggested that cinder cones might occur on other terrestrial bodies in the Solar system too; on the surface of Mars and the Moon. Stratovolcanoes (composite volcanoes) are tall conical mountains composed of lava flows and tephra in alternate layers, the strata that gives rise to the name. They are also known as composite volcanoes because they are created from multiple structures during different kinds of eruptions. Classic examples include Mount Fuji in Japan, Mayon Volcano in

2782-412: Is characterized by a rough, clinkery surface and is the typical texture of cooler basalt lava flows. Pāhoehoe is characterized by its smooth and often ropey or wrinkly surface and is generally formed from more fluid lava flows. Pāhoehoe flows are sometimes observed to transition to ʻaʻa flows as they move away from the vent, but never the reverse. More silicic lava flows take the form of block lava, where

2889-554: Is derived from the name of Vulcano , a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan , the god of fire in Roman mythology . The study of volcanoes is called volcanology , sometimes spelled vulcanology . According to the theory of plate tectonics, Earth's lithosphere , its rigid outer shell, is broken into sixteen larger and several smaller plates. These are in slow motion, due to convection in

2996-567: Is expressed using the volcanic explosivity index (VEI), which ranges from 0 for Hawaiian-type eruptions to 8 for supervolcanic eruptions. As of December 2022 , the Smithsonian Institution 's Global Volcanism Program database of volcanic eruptions in the Holocene Epoch (the last 11,700 years) lists 9,901 confirmed eruptions from 859 volcanoes. The database also lists 1,113 uncertain eruptions and 168 discredited eruptions for

3103-708: Is located near the village of Vathy but the main port is at Methana, also called Arsinoe in Ptolemaic times, with a fort on the islet of Nisaki. A coastal fortress called Akropolis Oga is located near Kypseli . A Mycenaean settlement was excavated by Helene Konstolakis-Jiannopoulou in 1990 along with the chapel of Agios Konstantinos and Elenis. Selected artifacts can be visited in the museums of Poros island and in Piraeus. This site dates between 1500 and 1300 BC. Methana ( Ancient Greek : τὰ Μέθανα , tà Méthana ), Methone ( Μεθώνη , Methṓnē ), or Methene ( Μεθήνη , Methḗnē )

3210-524: Is one of the several tuyas in the area of the Tuya River and Tuya Range in northern British Columbia. Tuya Butte was the first such landform analysed and so its name has entered the geological literature for this kind of volcanic formation. The Tuya Mountains Provincial Park was recently established to protect this unusual landscape, which lies north of Tuya Lake and south of the Jennings River near

3317-564: Is the epitome of a mourning widow. Her and Nephthys's love and grief for their brother help restore him to life, as does Isis's recitation of magical spells . Funerary texts contain speeches by Isis in which she expresses her sorrow at Osiris's death, her sexual desire for him, and even anger that he has left her. All these emotions play a part in his revival, as they are meant to stir him into action. Finally, Isis restores breath and life to Osiris's body and copulates with him, conceiving their son, Horus . After this point Osiris lives on only in

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3424-526: Is treated as the mother of Horus even in the earliest copies of the Pyramid Texts. Yet there are signs that Hathor was originally regarded as his mother, and other traditions make an elder form of Horus the son of Nut and a sibling of Isis and Osiris. Isis may only have come to be Horus's mother as the Osiris myth took shape during the Old Kingdom, but through her relationship with him she came to be seen as

3531-466: Is typically low in silica, shield volcanoes are more common in oceanic than continental settings. The Hawaiian volcanic chain is a series of shield cones, and they are common in Iceland , as well. Lava domes are built by slow eruptions of highly viscous lava. They are sometimes formed within the crater of a previous volcanic eruption, as in the case of Mount St. Helens , but can also form independently, as in

3638-600: The Cascade Volcanoes or the Japanese Archipelago , or the eastern islands of Indonesia . Hotspots are volcanic areas thought to be formed by mantle plumes , which are hypothesized to be columns of hot material rising from the core-mantle boundary. As with mid-ocean ridges, the rising mantle rock experiences decompression melting which generates large volumes of magma. Because tectonic plates move across mantle plumes, each volcano becomes inactive as it drifts off

3745-445: The Duat , or underworld. But by producing a son and heir to avenge his death and carry out funerary rites for him, Isis has ensured that her husband will endure in the afterlife. Isis's role in afterlife beliefs was based on that in the myth. She helped to restore the souls of deceased humans to wholeness as she had done for Osiris. Like other goddesses, such as Hathor , she also acted as

3852-742: The Fifth Dynasty ( c.  2494–2345 BCE ). An inscription that may refer to Isis dates to the reign of Nyuserre Ini during that period, and she appears prominently in the Pyramid Texts , which began to be written down at the end of the dynasty and whose content may have developed much earlier. Several passages in the Pyramid Texts link Isis with the region of the Nile Delta near Behbeit el-Hagar and Sebennytos , and her cult may have originated there. Many scholars have focused on Isis's name in trying to determine her origins. Her Egyptian name

3959-455: The Greek War of Independence , hundreds of refugees, mainly women and children, found refuge in the sparsely populated peninsula of Methana, so that the population of Methana rose from 500-600 in the pre-revolution years to 1,349 in 1830. In 1826-27 Charles Fabvier built a fortress on the isthmus of Methana, probably to protect his troops. In 1834 Methana became a municipality which was annexed to

4066-618: The Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide past one another. Large eruptions can affect atmospheric temperature as ash and droplets of sulfuric acid obscure the Sun and cool Earth's troposphere . Historically, large volcanic eruptions have been followed by volcanic winters which have caused catastrophic famines. Other planets besides Earth have volcanoes. For example, volcanoes are very numerous on Venus. Mars has significant volcanoes. In 2009,

4173-458: The Navigium Isidis , as well as initiation ceremonies resembling those of other Greco-Roman mystery cults . Some of her devotees said she encompassed all feminine divine powers in the world. The worship of Isis was ended by the rise of Christianity in the fourth through sixth centuries CE. Her worship may have influenced Christian beliefs and practices such as the veneration of Mary , but

4280-824: The landform and may give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Kīlauea in Hawaii. Volcanic craters are not always at the top of a mountain or hill and may be filled with lakes such as with Lake Taupō in New Zealand. Some volcanoes can be low-relief landform features, with the potential to be hard to recognize as such and be obscured by geological processes. Other types of volcano include cryovolcanoes (or ice volcanoes), particularly on some moons of Jupiter , Saturn , and Neptune ; and mud volcanoes , which are structures often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes except when

4387-530: The 2nd century, he saw a temple of Isis , and statutes of Hermes and Heracles in the agora . There are no written references to Methana in the Byzantine and Ottoman periods. Ruins of basilicas and churches from the late 6th or early 7th century have been found. It seems that there were two settlements in Methana in the Byzantine period, one at Panagitsa and another at Prophet Elias and at Helona. Another settlement seems to have existed west of Kounoupitsa , where

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4494-541: The Osiris myth. Isis is part of the Ennead of Heliopolis , a family of nine deities descended from the creator god, Atum or Ra . She and her siblings—Osiris, Set , and Nephthys —are the last generation of the Ennead, born to Geb , god of the earth, and Nut , goddess of the sky. The creator god, the world's original ruler, passes down his authority through the male generations of the Ennead, so that Osiris becomes king. Isis, who

4601-843: The Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift , the Wells Gray-Clearwater volcanic field , and the Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary , 3,000 kilometres (1,900 mi) deep within Earth. This results in hotspot volcanism , of which

4708-612: The Philippines, and Mount Vesuvius and Stromboli in Italy. Ash produced by the explosive eruption of stratovolcanoes has historically posed the greatest volcanic hazard to civilizations. The lavas of stratovolcanoes are higher in silica, and therefore much more viscous, than lavas from shield volcanoes. High-silica lavas also tend to contain more dissolved gas. The combination is deadly, promoting explosive eruptions that produce great quantities of ash, as well as pyroclastic surges like

4815-609: The USGS defines a volcano as active whenever subterranean indicators, such as earthquake swarms , ground inflation, or unusually high levels of carbon dioxide or sulfur dioxide are present. The USGS defines a dormant volcano as any volcano that is not showing any signs of unrest such as earthquake swarms, ground swelling, or excessive noxious gas emissions, but which shows signs that it could yet become active again. Many dormant volcanoes have not erupted for thousands of years, but have still shown signs that they may be likely to erupt again in

4922-503: The boundary with the Yukon Territory . Mud volcanoes (mud domes) are formations created by geo-excreted liquids and gases, although several processes may cause such activity. The largest structures are 10 kilometres in diameter and reach 700 meters high. The material that is expelled in a volcanic eruption can be classified into three types: The concentrations of different volcanic gases can vary considerably from one volcano to

5029-402: The case of Lassen Peak . Like stratovolcanoes, they can produce violent, explosive eruptions, but the lava generally does not flow far from the originating vent. Cryptodomes are formed when viscous lava is forced upward causing the surface to bulge. The 1980 eruption of Mount St. Helens was an example; lava beneath the surface of the mountain created an upward bulge, which later collapsed down

5136-473: The church of Agia Barbara is located and the churches of Agios Dimitrios and Agios Ioannis the Theologian, built in the 13th century and frescoed, are located. It seems that the peninsula was not affected by Slavic invasions, but later in medieval times it was affected by raids. During the 14th century, a period in which the population of the region was diluted, Arvanites settled on the Methana peninsula. During

5243-464: The distinctive traits of their deity more than on her universality, whereas some Egyptian hymns to Isis treat other goddesses in cult centers from across Egypt and the Mediterranean as manifestations of her. A text in her temple at Dendera says "in each nome it is she who is in every town, in every nome with her son Horus." In Ancient Egyptian art , Isis was most commonly depicted as a woman with

5350-772: The enormous area they cover, and subsequent concealment under vegetation and glacial deposits, supervolcanoes can be difficult to identify in the geologic record without careful geologic mapping . Known examples include Yellowstone Caldera in Yellowstone National Park and Valles Caldera in New Mexico (both western United States); Lake Taupō in New Zealand; Lake Toba in Sumatra , Indonesia; and Ngorongoro Crater in Tanzania. Volcanoes that, though large, are not large enough to be called supervolcanoes, may also form calderas in

5457-527: The epitome of maternal devotion. In the developed form of the myth, Isis gives birth to Horus, after a long pregnancy and a difficult labor, in the papyrus thickets of the Nile Delta. As her child grows she must protect him from Set and many other hazards—snakes, scorpions, and simple illness. In some texts, Isis travels among humans and must seek their help. According to one such story, seven minor scorpion deities travel with and guard her. They take revenge on

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5564-471: The evidence for this influence is ambiguous and often controversial. Isis continues to appear in Western culture , particularly in esotericism and modern paganism , often as a personification of nature or the feminine aspect of divinity. Whereas some Egyptian deities appeared in the late Predynastic Period (before c.  3100 BCE ), neither Isis nor her husband Osiris were mentioned by name before

5671-431: The flow is covered with angular, vesicle-poor blocks. Rhyolitic flows typically consist largely of obsidian . Tephra is made when magma inside the volcano is blown apart by the rapid expansion of hot volcanic gases. Magma commonly explodes as the gas dissolved in it comes out of solution as the pressure decreases when it flows to the surface . These violent explosions produce particles of material that can then fly from

5778-448: The foremost Egyptian deity during the Middle and New Kingdoms, also took on the role of Kamutef, and when he was in this form, Isis often acted as his consort. Apis , a bull that was worshipped as a living god at Memphis , was said to be Isis's son, fathered by a form of Osiris known as Osiris-Apis. The biological mother of each Apis bull was thus known as the "Isis cow". Isis was said to be

5885-592: The formation of a submarine volcano off the coast of Mayotte . Subglacial volcanoes develop underneath ice caps . They are made up of lava plateaus capping extensive pillow lavas and palagonite . These volcanoes are also called table mountains, tuyas , or (in Iceland) mobergs. Very good examples of this type of volcano can be seen in Iceland and in British Columbia . The origin of the term comes from Tuya Butte , which

5992-431: The frontier with Nubian peoples who raided Egypt, she was described as the protectress of the entire nation, more effective in battle than "millions of soldiers", supporting Ptolemaic kings and Roman emperors in their efforts to subdue Egypt's enemies. Isis was also known for her magical power , which enabled her to revive Osiris and to protect and heal Horus, and for her cunning. By virtue of her magical knowledge, she

6099-568: The future. In an article justifying the re-classification of Alaska's Mount Edgecumbe volcano from "dormant" to "active", volcanologists at the Alaska Volcano Observatory pointed out that the term "dormant" in reference to volcanoes has been deprecated over the past few decades and that "[t]he term "dormant volcano" is so little used and undefined in modern volcanology that the Encyclopedia of Volcanoes (2000) does not contain it in

6206-461: The glossaries or index", however the USGS still widely employs the term. Previously a volcano was often considered to be extinct if there were no written records of its activity. Such a generalization is inconsistent with observation and deeper study, as has occurred recently with the unexpected eruption of the Chaitén volcano in 2008. Modern volcanic activity monitoring techniques, and improvements in

6313-492: The interior of a continent and lead to rifting. Early stages of rifting are characterized by flood basalts and may progress to the point where a tectonic plate is completely split. A divergent plate boundary then develops between the two halves of the split plate. However, rifting often fails to completely split the continental lithosphere (such as in an aulacogen ), and failed rifts are characterized by volcanoes that erupt unusual alkali lava or carbonatites . Examples include

6420-465: The king nursing at Isis's breast; her milk not only healed her child, but symbolized his divine right to rule. Royal ideology increasingly emphasized the importance of queens as earthly counterparts of the goddesses who served as wives to the king and mothers to his heirs. Initially the most important of these goddesses was Hathor, whose attributes in art were incorporated into queens' crowns. But because of her own mythological links with queenship, Isis too

6527-513: The last volcanic eruption in Methana. The peninsula is the northwesternmost of the arc of the Aegean islands of which the active volcanic areas are Methana, Milos , Santorini and Nisyros . In the future, Methana (and the area of the Saronic gulf ) may expect other volcanic eruptions. Since 1991, the peninsula has been investigated by the team of ETH Zürich geologically and cartographically. From this,

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6634-501: The late New Kingdom. Various Ptolemaic funerary texts emphasize that Isis took the active role in Horus's conception by sexually stimulating her inert husband, some tomb decoration from the Roman period in Egypt depicts Isis in a central role in the afterlife, and a funerary text from that era suggests that women were thought able to join the retinue of Isis and Nephthys in the afterlife. Isis

6741-427: The length and quality of human lives. Horus was equated with each living pharaoh and Osiris with the pharaoh's deceased predecessors. Isis was therefore the mythological mother and wife of kings. In the Pyramid Texts her primary importance to the king was as one of the deities who protected and assisted him in the afterlife. Her prominence in royal ideology grew in the New Kingdom. Temple reliefs from that time on show

6848-419: The mid-oceanic ridge is above sea level, volcanic islands are formed, such as Iceland . Subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. The oceanic plate subducts (dives beneath the continental plate), forming a deep ocean trench just offshore. In a process called flux melting , water released from the subducting plate lowers the melting temperature of

6955-545: The modelling of the factors that produce eruptions, have helped the understanding of why volcanoes may remain dormant for a long time, and then become unexpectedly active again. The potential for eruptions, and their style, depend mainly upon the state of the magma storage system under the volcano, the eruption trigger mechanism and its timescale. For example, the Yellowstone volcano has a repose/recharge period of around 700,000 years, and Toba of around 380,000 years. Vesuvius

7062-585: The moon, possibly because she was linked with the Greek lunar goddess Artemis by a shared connection with an Egyptian fertility goddess, Bastet . In hymns inscribed at Philae she is called the "Lady of Heaven" whose dominion over the sky parallels Osiris's rule over the Duat and Horus's kingship on earth. In Ptolemaic times Isis's sphere of influence could include the entire cosmos. As the deity that protected Egypt and endorsed its king, she had power over all nations, and as

7169-415: The most dangerous type, are very rare; four are known from the last million years , and about 60 historical VEI 8 eruptions have been identified in the geologic record over millions of years. A supervolcano can produce devastation on a continental scale, and severely cool global temperatures for many years after the eruption due to the huge volumes of sulfur and ash released into the atmosphere. Because of

7276-553: The mother of Bastet by Ra . A story in the Westcar Papyrus from the Middle Kingdom includes Isis among a group of goddesses who serve as midwives during the delivery of three future kings. She serves a similar role in New Kingdom texts that describe the divinely ordained births of reigning pharaohs. In the Westcar Papyrus, Isis calls out the names of the three children as they are born. Barbara S. Lesko sees this story as

7383-438: The mud volcano is actually a vent of an igneous volcano. Volcanic fissure vents are flat, linear fractures through which lava emerges. Shield volcanoes, so named for their broad, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent. They generally do not explode catastrophically but are characterized by relatively gentle effusive eruptions . Since low-viscosity magma

7490-452: The next. Water vapour is typically the most abundant volcanic gas, followed by carbon dioxide and sulfur dioxide . Other principal volcanic gases include hydrogen sulfide , hydrogen chloride , and hydrogen fluoride . A large number of minor and trace gases are also found in volcanic emissions, for example hydrogen , carbon monoxide , halocarbons , organic compounds, and volatile metal chlorides. The form and style of an eruption of

7597-867: The north side of the mountain. Cinder cones result from eruptions of mostly small pieces of scoria and pyroclastics (both resemble cinders, hence the name of this volcano type) that build up around the vent. These can be relatively short-lived eruptions that produce a cone-shaped hill perhaps 30 to 400 metres (100 to 1,300 ft) high. Most cinder cones erupt only once and some may be found in monogenetic volcanic fields that may include other features that form when magma comes into contact with water such as maar explosion craters and tuff rings . Cinder cones may form as flank vents on larger volcanoes, or occur on their own. Parícutin in Mexico and Sunset Crater in Arizona are examples of cinder cones. In New Mexico , Caja del Rio

7704-541: The ocean surface as new islands or floating pumice rafts . In May and June 2018, a multitude of seismic signals were detected by earthquake monitoring agencies all over the world. They took the form of unusual humming sounds, and some of the signals detected in November of that year had a duration of up to 20 minutes. An oceanographic research campaign in May 2019 showed that the previously mysterious humming noises were caused by

7811-420: The ocean surface, due to the rapid cooling effect and increased buoyancy in water (as compared to air), which often causes volcanic vents to form steep pillars on the ocean floor. Hydrothermal vents are common near these volcanoes, and some support peculiar ecosystems based on chemotrophs feeding on dissolved minerals. Over time, the formations created by submarine volcanoes may become so large that they break

7918-471: The ocean's surface. In the deep ocean basins, the tremendous weight of the water prevents the explosive release of steam and gases; however, submarine eruptions can be detected by hydrophones and by the discoloration of water because of volcanic gases . Pillow lava is a common eruptive product of submarine volcanoes and is characterized by thick sequences of discontinuous pillow-shaped masses which form underwater. Even large submarine eruptions may not disturb

8025-462: The one that destroyed the city of Saint-Pierre in Martinique in 1902. They are also steeper than shield volcanoes, with slopes of 30–35° compared to slopes of generally 5–10°, and their loose tephra are material for dangerous lahars . Large pieces of tephra are called volcanic bombs . Big bombs can measure more than 1.2 metres (4 ft) across and weigh several tons. A supervolcano is defined as

8132-425: The overlying mantle wedge, thus creating magma . This magma tends to be extremely viscous because of its high silica content, so it often does not reach the surface but cools and solidifies at depth . When it does reach the surface, however, a volcano is formed. Thus subduction zones are bordered by chains of volcanoes called volcanic arcs . Typical examples are the volcanoes in the Pacific Ring of Fire , such as

8239-595: The plume, and new volcanoes are created where the plate advances over the plume. The Hawaiian Islands are thought to have been formed in such a manner, as has the Snake River Plain , with the Yellowstone Caldera being part of the North American plate currently above the Yellowstone hotspot . However, the mantle plume hypothesis has been questioned. Sustained upwelling of hot mantle rock can develop under

8346-400: The preeminent goddess of earlier times, Isis was portrayed wearing Hathor's headdress: a sun disk between the horns of a cow . In the first millennium BCE, Osiris and Isis became the most widely worshipped Egyptian deities, and Isis absorbed traits from many other goddesses. Rulers in Egypt and its southern neighbor Nubia built temples dedicated primarily to Isis, and her temple at Philae

8453-529: The primary roles to local deities. At Philae, Isis is described as the creator in the same way that older texts speak of the work of the god Ptah , who was said to have designed the world with his intellect and sculpted it into being. Like him, Isis formed the cosmos "through what her heart conceived and her hands created". Like other deities throughout Egyptian history, Isis had many forms in her individual cult centers, and each cult center emphasized different aspects of her character. Local Isis cults focused on

8560-509: The provider of rain, she enlivened the natural world. The Philae hymn that initially calls her ruler of the sky goes on to expand her authority, so at its climax her dominion encompasses the sky, earth, and Duat. It says her power over nature nourishes humans, the blessed dead, and the gods. Other, Greek-language hymns from Ptolemaic Egypt call her "the beautiful essence of all the gods". In the course of Egyptian history, many deities, major and minor, had been described in similar grand terms. Amun

8667-508: The province of Kalavria, consisting of the municipalities of Methana, Troizina, Dryopi and Kalavria. [REDACTED]  This article incorporates text from a publication now in the public domain :  Smith, William , ed. (1854–1857). "Methana". Dictionary of Greek and Roman Geography . London: John Murray. Volcano A volcano is a rupture in the crust of a planetary-mass object , such as Earth , that allows hot lava , volcanic ash , and gases to escape from

8774-435: The same time interval. Volcanoes vary greatly in their level of activity, with individual volcanic systems having an eruption recurrence ranging from several times a year to once in tens of thousands of years. Volcanoes are informally described as erupting , active , dormant , or extinct , but the definitions of these terms are not entirely uniform among volcanologists. The level of activity of most volcanoes falls upon

8881-485: The same way; they are often described as "caldera volcanoes". Submarine volcanoes are common features of the ocean floor. Volcanic activity during the Holocene Epoch has been documented at only 119 submarine volcanoes, but there may be more than one million geologically young submarine volcanoes on the ocean floor. In shallow water, active volcanoes disclose their presence by blasting steam and rocky debris high above

8988-622: The solidified erupted material that makes up the mantle of a volcano may be stripped away that its inner anatomy becomes apparent. Using the metaphor of biological anatomy , such a process is called "dissection". Cinder Hill , a feature of Mount Bird on Ross Island , Antarctica , is a prominent example of a dissected volcano. Volcanoes that were, on a geological timescale, recently active, such as for example Mount Kaimon in southern Kyūshū , Japan , tend to be undissected. Eruption styles are broadly divided into magmatic, phreatomagmatic, and phreatic eruptions. The intensity of explosive volcanism

9095-463: The start of the Nile flood , gave Sopdet a close connection with the flood and the resulting growth of plants. Partly because of her relationship with Sopdet, Isis was also linked with the flood, which was sometimes equated with the tears she shed for Osiris. By Ptolemaic times she was connected with rain, which Egyptian texts call a "Nile in the sky"; with the sun as the protector of Ra's barque; and with

9202-453: The story seems to treat her as having such abilities even before learning his name. Many of the roles Isis acquired gave her an important position in the sky. Passages in the Pyramid Texts connect Isis closely with Sopdet , the goddess representing the star Sirius , whose relationship with her husband Sah —the constellation Orion —and their son Sopdu parallels Isis's relations with Osiris and Horus. Sirius's heliacal rising , just before

9309-406: The surrounding areas, and initially not seismically monitored before its unanticipated and catastrophic eruption of 1991. Two other examples of volcanoes that were once thought to be extinct, before springing back into eruptive activity were the long-dormant Soufrière Hills volcano on the island of Montserrat , thought to be extinct until activity resumed in 1995 (turning its capital Plymouth into

9416-434: The theory of plate tectonics. For example, some volcanoes are polygenetic with more than one period of activity during their history; other volcanoes that become extinct after erupting exactly once are monogenetic (meaning "one life") and such volcanoes are often grouped together in a geographical region. At the mid-ocean ridges , two tectonic plates diverge from one another as hot mantle rock creeps upwards beneath

9523-444: The thinned oceanic crust . The decrease of pressure in the rising mantle rock leads to adiabatic expansion and the partial melting of the rock, causing volcanism and creating new oceanic crust. Most divergent plate boundaries are at the bottom of the oceans, and so most volcanic activity on Earth is submarine, forming new seafloor . Black smokers (also known as deep sea vents) are evidence of this kind of volcanic activity. Where

9630-404: The throne was considered the king's mother, and thus a goddess, because of its power to make a man into a king. Other scholars, such as Jürgen Osing and Klaus P. Kuhlmann, have disputed this interpretation, because of dissimilarities between Isis's name and the word for a throne or a lack of evidence that the throne was ever deified. The cycle of myth surrounding Osiris's death and resurrection

9737-415: The typical attributes of a goddess: a sheath dress, a staff of papyrus in one hand, and an ankh sign in the other. Her original headdress was the throne sign used in writing her name. She and Nephthys often appear together, particularly when mourning Osiris's death, supporting him on his throne, or protecting the sarcophagi of the dead. In these situations their arms are often flung across their faces, in

9844-431: The underlying ductile mantle , and most volcanic activity on Earth takes place along plate boundaries, where plates are converging (and lithosphere is being destroyed) or are diverging (and new lithosphere is being created). During the development of geological theory, certain concepts that allowed the grouping of volcanoes in time, place, structure and composition have developed that ultimately have had to be explained in

9951-492: The volcano. Solid particles smaller than 2 mm in diameter ( sand-sized or smaller) are called volcanic ash. Tephra and other volcaniclastics (shattered volcanic material) make up more of the volume of many volcanoes than do lava flows. Volcaniclastics may have contributed as much as a third of all sedimentation in the geologic record. The production of large volumes of tephra is characteristic of explosive volcanism. Through natural processes, mainly erosion , so much of

10058-424: The volcanoes of the East African Rift . A volcano needs a reservoir of molten magma (e.g. a magma chamber), a conduit to allow magma to rise through the crust, and a vent to allow the magma to escape above the surface as lava. The erupted volcanic material (lava and tephra) that is deposited around the vent is known as a volcanic edifice , typically a volcanic cone or mountain. The most common perception of

10165-524: The wider Mediterranean world. Isis's Greek devotees ascribed to her traits taken from Greek deities , such as the invention of marriage and the protection of ships at sea. As Hellenistic culture was absorbed by Rome in the first century BCE, the cult of Isis became a part of Roman religion . Her devotees were a small proportion of the Roman Empire 's population but were found all across its territory. Her following developed distinctive festivals such as

10272-785: The wrong. In later texts, she uses her powers of transformation to fight and destroy Set and his followers. Many stories about Isis appear as historiolae , prologues to magical texts that describe mythic events related to the goal that the spell aims to accomplish. In one spell, Isis creates a snake that bites Ra, who is older and greater than she is, and makes him ill with its venom. She offers to cure Ra if he will tell her his true, secret name —a piece of knowledge that carries with it incomparable power. After much coercion, Ra tells her his name, which she passes on to Horus, bolstering his royal authority. The story may be meant as an origin story to explain why Isis's magical ability surpasses that of other deities, but because she uses magic to subdue Ra,

10379-454: Was a religious center for Egyptians and Nubians alike. Her reputed magical power was greater than that of all other gods, and she was said to govern the natural world and wield power over fate itself. In the Hellenistic period (323–30 BCE), when Egypt was ruled and settled by Greeks , Isis was worshipped by Greeks and Egyptians, along with a new god, Serapis . Their worship diffused into

10486-421: Was described by Roman writers as having been covered with gardens and vineyards before its unexpected eruption of 79 CE , which destroyed the towns of Herculaneum and Pompeii . Accordingly, it can sometimes be difficult to distinguish between an extinct volcano and a dormant (inactive) one. Long volcano dormancy is known to decrease awareness. Pinatubo was an inconspicuous volcano, unknown to most people in

10593-518: Was first mentioned in the Old Kingdom ( c.  2686  – c.  2181 BCE ) as one of the main characters of the Osiris myth , in which she resurrects her slain brother and husband, the divine king Osiris , and produces and protects his heir, Horus . She was believed to help the dead enter the afterlife as she had helped Osiris, and she was considered the divine mother of the pharaoh , who

10700-613: Was first recorded in the Pyramid Texts and grew into the most elaborate and influential of all Egyptian myths . Isis plays a more active role in this myth than the other protagonists, so as it developed in literature from the New Kingdom ( c.  1550 –1070 BCE) to the Ptolemaic Period (305–30 BCE), she became the most complex literary character of all Egyptian deities. At the same time, she absorbed characteristics from many other goddesses, broadening her significance well beyond

10807-463: Was given the same titles and regalia as human queens. Isis's actions in protecting Osiris against Set became part of a larger, more warlike aspect of her character. New Kingdom funerary texts portray Isis in the barque of Ra as he sails through the underworld, acting as one of several deities who subdue Ra's archenemy, Apep . Kings also called upon her protective magical power against human enemies. In her Ptolemaic temple at Philae , which lay near

10914-530: Was in the territory of Troezen . In his History of the Peloponnesian War , Thucydides tells of an Athenian expeditionary force under Nicias that after defeating Corinth (in 425 BC) built a wall across the isthmus to cut the Methana peninsula off from the mainland. In the Hellenistic period, the peninsula became one of the Ptolemaic bases in the Aegean when it was renamed Arsinoe. When Pausanias visited in

11021-486: Was likened to Horus. Her maternal aid was invoked in healing spells to benefit ordinary people. Originally, she played a limited role in royal rituals and temple rites, although she was more prominent in funerary practices and magical texts. She was usually portrayed in art as a human woman wearing a throne-like hieroglyph on her head. During the New Kingdom ( c.  1550  – c.  1070 BCE ), as she took on traits that originally belonged to Hathor ,

11128-520: Was most commonly described this way in the New Kingdom, whereas in Roman Egypt such terms tended to be applied to Isis. Such texts do not deny the existence of other deities but treat them as aspects of the supreme deity, a type of theology sometimes called " summodeism ". In the Late, Ptolemaic, and Roman Periods, many temples contained a creation myth that adapted long-standing ideas about creation to give

11235-460: Was said to be "more clever than a million gods". In several episodes in the New Kingdom story " The Contendings of Horus and Set ", Isis uses these abilities to outmaneuver Set during his conflict with her son. On one occasion, she transforms into a young woman who tells Set she is involved in an inheritance dispute similar to Set's usurpation of Osiris's crown. When Set calls this situation unjust, Isis taunts him, saying he has judged himself to be in

11342-428: Was syncretized with the fertility god Min , so Isis was regarded as Min's mother. A form of Min known as Kamutef, "bull of his mother", who represented the cyclical regeneration of the gods and of kingship, was said to impregnate his mother to engender himself. Thus, Isis was also regarded as Min's consort. The same ideology of kingship may lie behind a tradition, found in a few texts, that Horus raped Isis. Amun ,

11449-569: Was written as 𓊨𓏏𓆇𓁐 ( ꜣst ), the pronunciation of which changed over time: Rūsat > Rūsaʾ > ʾŪsaʾ > ʾĒsə , which became ⲎⲤⲈ ( Ēse ) in the Coptic form of Egyptian , Wusa in the Meroitic language of Nubia, and Ἶσις , on which her modern name is based, in Greek . The hieroglyphic writing of her name incorporates the sign for a throne, which Isis also wears on her head as

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