Instruct: Given a question, retrieve passages that can help answer the question.
Query: Can lava kill you?
In 1993, a photographer attempting to take pictures of a lava ocean entry died, and several tourists were injured, when a lava bench collapsed. In 2000, two people were found dead near a lava ocean entry from Kīlauea, likely killed by laze. Sulfur Dioxide emissions can also be fatal, especially to people suffering from respiratory ailments. In 2018 lava spatter from Kīlauea broke a man's leg, and another 23 people on a tour boat were injured by a steam explosion at a lava ocean entry from the same eruption.
A supervolcano usually has a large caldera and can produce devastation on an enormous, sometimes continental, scale. Such volcanoes are able to severely cool global temperatures for many years after the eruption due to the huge volumes of sulfur and ash released into the atmosphere. They are the most dangerous type of volcano. Examples include Yellowstone Caldera in Yellowstone National Park and Valles Caldera in New Mexico (both western United States); Lake Taupo in New Zealand; Lake Toba in Sumatra, Indonesia; and Ngorongoro Crater in Tanzania. Because of the enormous area they may cover, supervolcanoes are hard to identify centuries after an eruption. Similarly, large igneous provinces are also considered supervolcanoes because of the vast amount of basalt lava erupted (even though the lava flow is non-explosive).
North of this area, on the slope of Mt Haszard, is Inferno Crater, filled with a striking pale blue lake of highly acidic water with a pH as low as 2.2. The crater was blasted into the side of the mountain as part of the 1886 Mount Tarawera eruption event and remains the site of the largest geyser-like feature in the world. Although the actual geyser plays at the bottom of the lake and cannot be seen, a handful of active fumaroles are visible on the shore and the cliff face behind the lake. The water level of this up-to- lake follows a complicated rhythmic cycle that is interconnected with the nearby Frying Pan Lake.
In recorded history, explosive eruptions at subduction zone (convergent-boundary) volcanoes have posed the greatest hazard to civilizations. Subduction-zone stratovolcanoes, such as Mount St. Helens, Mount Etna and Mount Pinatubo, typically erupt with explosive force: the magma is too stiff to allow easy escape of volcanic gases. As a consequence, the tremendous internal pressures of the trapped volcanic gases remain and intermingle in the pasty magma. Following the breaching of the vent and the opening of the crater, the magma degasses explosively. The magma and gases blast out with high speed and full force.
A massive supervolcano erupted at present-day Lake Toba around 70,000 BCE. It is believed to have caused a global volcanic winter and cooling of the climate, and subsequently led to a genetic bottleneck in human evolution, though this is still debated. The 1815 eruption of Mount Tambora and the 1883 eruption of Krakatoa were among the largest in recorded history. The former resulted in 92,000 deaths and created an umbrella of volcanic ash which spread and blanketed parts of the archipelago, and made much of Northern Hemisphere without summer in 1816. The latter produced the loudest sound in recorded history, and resulted in 36,000 deaths that are attributed to the eruption itself and the tsunamis it created. Significant additional effects were also felt around the world years after the eruption. Recent major disasters due to seismic activity include the 2004 Indian Ocean earthquake and the 2006 Yogyakarta earthquake.
Caves can be dangerous places; hypothermia, falling, flooding, falling rocks and physical exhaustion are the main risks. Rescuing people from underground is difficult and time-consuming, and requires special skills, training, and equipment. Full-scale cave rescues often involve the efforts of dozens of rescue workers (often other long-time cavers who have participated in specialized courses, as normal rescue staff are not sufficiently experienced in cave environments), who may themselves be put in jeopardy in effecting the rescue. This said, caving is not necessarily a high-risk sport (especially if it does not involve difficult climbs or diving). As in all physical sports, knowing one's limitations is key.
A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava, tephra, pumice and ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit craters called calderas. The lava flowing from stratovolcanoes typically cools and hardens before spreading far, due to high viscosity. The magma forming this lava is often felsic, having high-to-intermediate levels of silica (as in rhyolite, dacite, or andesite), with lesser amounts of less-viscous mafic magma. Extensive felsic lava flows are uncommon, but have travelled as far as .
The Talara Tar Seeps in Peru represent a similar scenario, and have also produced fossils of "Smilodon". Unlike in La Brea, many of the bones were broken or show signs of weathering. This may have been because the layers were shallower, so the thrashing of trapped animals damaged the bones of previously trapped animals. Many of the carnivores at Talara were juveniles, possibly indicating that inexperienced and less fit animals had a greater chance of being trapped. Though Lund thought accumulations of "Smilodon" and herbivore fossils in the Lagoa Santa Caves were due to the cats using the caves as dens, these are probably the result of animals dying on the surface, and water currents subsequently dragging their bones to the floor of the cave, but some individuals may also have died after becoming lost in the caves.
Inferno Crater Lake is a large hot spring located in the Waimangu Volcanic Rift Valley on the North Island of New Zealand, and the largest geyser-like feature in the world. The actual geyser is not visible, as it plays underwater at the bottom of the lake, however, fumaroles are visible on the lake's shore and the rock wall behind it.
Stratovolcanoes are sometimes called "composite volcanoes" because of their composite stratified structure built up from sequential outpourings of erupted materials. They are among the most common types of volcanoes, in contrast to the less common shield volcanoes. Two famous examples of stratovolcanoes are Krakatoa, known for its catastrophic eruption in 1883 and Vesuvius, whose eruption in AD79 caused destruction of Pompeii and Herculaneum in 79 AD. Both eruptions claimed thousands of lives. In modern times, Mount St. Helens and Mount Pinatubo have erupted catastrophically, with lesser losses of lives.
Jupiter's moon Io is the most volcanically active object in the solar system because of tidal interaction with Jupiter. It is covered with volcanoes that erupt sulfur, sulfur dioxide and silicate rock, and as a result, Io is constantly being resurfaced. Its lavas are the hottest known anywhere in the solar system, with temperatures exceeding 1,800 K (1,500 °C). In February 2001, the largest recorded volcanic eruptions in the solar system occurred on Io. Europa, the smallest of Jupiter's Galilean moons, also appears to have an active volcanic system, except that its volcanic activity is entirely in the form of water, which freezes into ice on the frigid surface. This process is known as cryovolcanism, and is apparently most common on the moons of the outer planets of the solar system.
Swimming in the pool at the bottom of the falls is discouraged. This is due both to occasional rockfalls and to the bacterial disease called Leptospirosis, which causes severe flu-like symptoms. Leptospirosis is found in freshwater and is common in tropical climates. In Hawaii, rats and mice often carry the disease and can easily transfer it to humans through their urine.
The Waimangu Volcanic Rift Valley is the hydrothermal system created on 10 June 1886 by the volcanic eruption of Mount Tarawera, on the North Island of New Zealand. It encompasses Lake Rotomahana, the site of the Pink and White Terraces, as well as the location of the Waimangu Geyser, which was active from 1900 to 1904. The area has been increasingly accessible as a tourist attraction and contains Frying Pan Lake, which is the largest hot spring in the world, and the steaming and usually pale blue Inferno Crater Lake, the largest geyser-like feature in the world although the geyser itself cannot be seen since it plays at the bottom of the lake.
Lōihi Seamount (also known as Lōʻihi) is an active submarine volcano about off the southeast coast of the island of Hawaii. The top of the seamount is about below sea level. This seamount is on the flank of Mauna Loa, the largest shield volcano on Earth. Lōihi, meaning "long" in Hawaiian, is the newest volcano in the Hawaiian-Emperor seamount chain, a string of volcanoes that stretches over northwest of Lōʻihi. Unlike most active volcanoes in the Pacific Ocean that make up the active plate margins on the Pacific Ring of Fire, Lōʻihi and the other volcanoes of the Hawaiian-Emperor seamount chain are hotspot volcanoes and formed well away from the nearest plate boundary. Volcanoes in the Hawaiian Islands arise from the Hawaii hotspot, and as the youngest volcano in the chain, Lōihi is the only Hawaiian volcano in the deep submarine preshield stage of development.
Magnesium is sold in stores in shaved or bar form. Shavings burn white-hot, are impossible to smother with carbon dioxide or sand, and can ignite even wet kindling. Solid bars are impossible to ignite under normal conditions (and difficult even with a welding torch), and are thus very safe to carry. Magnesium powder and shavings are pyrophoric (they oxidise rapidly when exposed to the air). It is dangerous to carry pre-shaved magnesium — at best, it loses potency, at worst, it can spontaneously ignite and is then nearly unquenchable. Magnesium bars are sometimes sold with a length of ferrocerium cast into one edge.
Laverbread () is a food product, made from an edible seaweed (littoral alga), consumed mainly in Wales as part of local traditional cuisine. The seaweed is commonly found around the west coast of Great Britain and east coast of Ireland along the Irish Sea, where it is known as slake. It is smooth in texture and forms delicate, sheetlike thalli, often clinging to rocks. The principal variety is porphyra ("Porphyra umbilicalis"). Porphyra (laver seaweed) is classified as red algae; it tends to be a brownish colour, but boils down to a dark green pulp when prepared. Laver seaweed has a high content of dietary minerals, particularly iodine and iron. The high iodine content gives the seaweed a distinctive flavour in common with olives and oysters.
Yellowstone National Park spans an area of , comprising lakes, canyons, rivers and mountain ranges. Yellowstone Lake is one of the largest high-elevation lakes in North America and is centered over the Yellowstone Caldera, the largest supervolcano on the continent. The caldera is considered an active volcano. It has erupted with tremendous force several times in the last two million years. Half of the world's geysers and hydrothermal features are in Yellowstone, fueled by this ongoing volcanism. Lava flows and rocks from volcanic eruptions cover most of the land area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining nearly-intact ecosystem in the Earth's northern temperate zone. In 1978, Yellowstone was named a UNESCO World Heritage Site.
Yellowstone National Park has one of the world's largest petrified forests, trees which were long ago buried by ash and soil and transformed from wood to mineral materials. This ash and other volcanic debris are believed to have come from the park area itself as the central part of Yellowstone is the massive caldera of a supervolcano. The park contains 290 waterfalls of at least , the highest being the Lower Falls of the Yellowstone River at .
The boomslang's venom is the most potent of all rear-fanged snakes in the world based on LD50. Although its venom may be more potent than some vipers and elapids, it causes fewer fatalities owing to various factors (for example, the fangs' effectiveness is not high compared with many other snakes: the venom dose delivered is low, and boomslangs are generally less aggressive in comparison to other venomous snakes such as cobras and mambas).
The "Lukina jama" cave is 1431 m deep (2013), the deepest cave in Croatia, 14th deepest cave in the world and the deepest cave in southeast Europe. At its foot, there are ponds and streams including one of the largest known colonies of subterranean leeches ("Erpobdella mestrovi"), which has been ascertained to represent a new species, genus and also family. Other species discovered in the system, include the air-breathing land snails "Zospeum tholussum". Like Lukina jama, Slovacka jama, Velebita and Meduza are also located at the "Hajdučki i Rožanski kukovi" special reserve, a dedicated part of the Sjeverni Velebit national park.
Stratovolcanoes or composite volcanoes are tall conical mountains composed of lava flows and other ejecta in alternate layers, the strata that gives rise to the name. Stratovolcanoes are also known as composite volcanoes because they are created from multiple structures during different kinds of eruptions. Strato/composite volcanoes are made of cinders, ash, and lava. Cinders and ash pile on top of each other, lava flows on top of the ash, where it cools and hardens, and then the process repeats. Classic examples include Mount Fuji in Japan, Mayon Volcano in the Philippines, and Mount Vesuvius and Stromboli in Italy.
Lava flows in the Northern Cordilleran Volcanic Province are among the least hazardous, even though they can be enormously destructive to property in their path. This is because lava generally moves slowly enough for people to get out of their way, though this is dependent on the viscosity of the lava. Lava flows typically have secondary hazards, including the destruction of buildings and ejection of volcanic gases. Forest fires started by lava flows are also a possibility in this part of Canada. The typical lava fountains in the Northern Cordilleran Volcanic Province are commonly associated with lava flows, but these do not normally reach heights more than a few hundred metres. Therefore, the dangers caused by lava fountains are only adjacent to the erupting volcano.
A lava child is a humanoid resembling a broadly-built man, but with a curious childlike appearance, with pinkish-white skin and a permanent smile on its face. A lava child is the unnatural offspring of a union between spirits of earth and fire. Metal objects pass through lava children without harming them as if the metal did not exist, and they can move through metal without hindrance. Any metal armor worn by a victim does nothing to protect the victim from the clawed hands or bites of lava children.
There are different forms of effusive lava that can provide different hazards. Pahoehoe lava is smooth and ropy while Aa lava is blocky and hard. Lava flows normally follow the topography, sinking into depressions and valleys and flowing down the volcano. Lava flows will bury roads farmlands and other forms of personal property. This lava could destroy homes, cars, and lives standing in the way. Lava flows are dangerous, however, they are slow moving and this gives people time to respond and evacuate out of immediate areas. People can mitigate this hazard by not moving to valleys or depressed areas around a volcano.
Lava flows from stratovolcanoes are generally not a significant threat to humans and animals because the highly viscous lava moves slowly enough for everyone to flee out of the path of flow. The lava flows are more of a threat to property. However, not all stratovolcanoes erupt viscous and sticky lava. Mount Nyiragongo is very dangerous because its magma has an unusually low silica content, making it quite fluid. Fluid lavas are typically associated with the formation of broad shield volcanoes such as those of Hawaii, but Nyiragongo has very steep slopes down which lava can flow at up to . Lava flows could melt down ice and glaciers that accumulated on the volcano's crater and upper slopes, generating massive lahar flows. Rarely, generally fluid lava could also generate a massive lava fountain, while lava of thicker viscosity can solidify within the vent, creating a block which can result in highly explosive eruptions.