木衛一的火山活動
Volcanology of Io

context: zh_tw: 在埃歐的阿米拉尼和瑪蘇比火山口曾經觀察道長達 300 公里的活躍熔岩流。相對的，被稱為 Lei-Kung Fluctus 的是較不活躍的熔岩流，覆蓋的面積廣達 125,000 平方公里，這個區域比尼加拉瓜略大一些。伽利略號未能測量熔岩流場的厚度，但是由在表面個別的斷裂處估計厚度大約是一米。在許多的例項中，活動中的熔岩流的表面在距離出氣孔數十到數百公里處斷裂，在出氣口和斷裂處之間偵測到的熱輻射總量相當的低，因此認為從出氣孔到斷裂處的熔岩流是在熔岩管內流動。通常，這些噴發都有穩定的噴發速率，但在許多流體主導的噴發點也觀察到劇烈的噴發。例如，航海家在 1979 年和伽利略號在 1996 年間觀察到普羅米修斯火山的熔岩流場的前緣就移動了 75 至 95 公里。通常由爆炸主導的熔岩流規模都比較小，但平均而言，這些複雜熔岩流場的規模仍然比在地球上相似的熔岩場要大。在伽利略任務期間，觀察到普羅米修斯和阿米拉尼的熔岩覆蓋速率是每秒 35 至 60 平方米，相較於地球的啟勞亞的覆蓋率只有 0.6 平方米。
en: Active flow fields more than 300 kilometres (190 mi) long have been observed on Io at Amirani and Masubi. A relatively inactive flow field named Lei-Kung Fluctus covers more than 125,000 square kilometres (48,000 sq mi), an area slightly larger than Nicaragua. The thickness of flow fields was not determined by Galileo, but the individual breakouts on their surface are likely to be 1 m (3 ft) thick. In many cases, active lava breakouts flow out onto the surface at locations tens to hundreds of kilometres from the source vent, with low amounts of thermal emission observed between it and the breakout. This suggests that lava flows through lava tubes from the source vent to the breakout.Although these eruptions generally have a steady eruption rate, larger outbreaks of lava have been observed at many flow-dominated eruption sites. For example, the leading edge of the Prometheus flow field moved 75 to 95 kilometres (47 to 59 mi) between observations by Voyager in 1979 and Galileo in 1996. Although generally dwarfed by explosion-dominated eruptions, the average flow rate at these compound flow fields is much greater than what is observed at similar contemporary lava flows on Earth. Average surface coverage rates of 35–60 square metres (380–650 sq ft) per second were observed at Prometheus and Amirani during the Galileo mission, compared to 0.6 square metres (6.5 sq ft) per second at Kīlauea.
qas: question: zh_tw: Lei-Kung Fluctus 的熔岩流有多大？
en: How large is the flow field of Lei-Kung Fluctus?
answers: zh_tw: text: 125,000 平方公里
en: text: 125,000 square kilometres (48,000 sq mi)

context: zh_tw: 當有更多的爆炸時，熔岩噴泉的階段也許可以持續幾天或一個星期，爆炸主導的噴發可以持續幾星期到幾個月，造成大面積的矽酸鹽熔岩流。在 1997 年主要來自 Pillan 火山口西北的一道裂縫，持續了半個月的噴發，造成超過 31 立方公里的新鮮熔岩，稍後充斥在 Pillan 火山內的地板上。「伽利略號」的觀測認為在 Pillan 火山在 1997 年噴發時的熔岩覆蓋率是每秒 1,000 至 3,000 平方米，熔岩流的厚度被發現是 10 米，相較之下普羅米修斯和安米拉尼平坦的地基只有 1 米的厚度。相似的，「伽利略號」在 2001 年觀察到托爾的熔岩流也是如此的迅速，這樣的流速在地球上也曾在 1783 年出現在冰島的噴發湖，造成大面積的玄武岩散佈。
en: Although the more explosive, lava-fountaining stage may last only a few days to a week, explosion-dominated eruptions can continue for weeks to months, producing large, voluminous silicate lava flows. A major eruption in 1997 from a fissure north-west of Pillan Patera produced more than 31 cubic kilometres (7.4 cu mi) of fresh lava over a ​2 1⁄2- to ​5 1⁄2-month period, and later flooded the floor of Pillan Patera. Observations by Galileo suggest lava coverage rates at Pillan between 1,000 and 3,000 square metres (11,000 and 32,000 sq ft) per second during the 1997 eruption. The Pillan flow was found to be 10 m (33 ft) thick, compared to the 1 m (3 ft) thick flows observed at the inflated fields at Prometheus and Amirani. Similar, rapidly emplaced lava flows were observed by Galileo at Thor in 2001. Such flow rates are similar to those seen at Iceland's Laki eruption in 1783 and in terrestrial flood basalt eruptions.Explosion-dominated eruptions can produce dramatic (but often short-lived) surface changes around the eruption site, such as large pyroclastic and plume deposits produced as gas exsolves from lava fountains. The 1997 Pillan eruption produced a 400 km (250 mi) wide deposit of dark, silicate material and bright sulfur dioxide. The Tvashtar eruptions of 2000 and 2007 generated a 330 km (210 mi) tall plume that deposited a ring of red sulfur and sulfur dioxide 1,200 km (750 mi) wide. Despite the dramatic appearance of these features, without continuous resupply of material, the vent surroundings often revert to their pre-eruption appearance over a period of months (in the case of Grian Patera) or years (as at Pillan Patera).
qas: question: zh_tw: 1997 年噴出的岩漿有多遠？
en: how far did the lava from the 1997 eruption cover?
answers: zh_tw: text: 31 立方公里
en: text: 31 cubic kilometres (7.4 cu mi)