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火山热科学的事实和其他碎片


编辑:admin 时间:2018-09-22

Volcanoes are some of the most amazing geological features but quite often, they腾讯体育’;re misunderstood or not understood at all。 Here we’;ll get to know them a bit better, starting with the basic facts and the moving onto cool and surprising facts, and of course, continuing with everyone’;s favorite (from a distance): eruptions。

Basic Volcano Facts

1。 Volcanoes are ruptures in the Earth’;s crust。 Our planet’;s crust is split into 17 major tectonic plates, and almost all volcanoes occur at the edges between these plates。

2。 There are three types of volcanoes: stratovolcano (conical volcano consisting of layers of solid lava), cinder cone volcano (steep hill of tephra that accumulates around the vent) and shield volcano (built entirely or almost entirely from fluid lava vents)。

3。 Volcanoes can be active (with eruptions in the past 10,000 years), dormant (no eruptions in the past 10,000 years, but could wake up) and extinct (unlikely to ever erupt again)。 However, active volcanoes can become dormant and extinct, and dormant volcanoes can wake up。 ***ore 79 AD, Vesuvius was considered dormant and its eruption was catastrophic。 Knowing whether a volcano is truly extinct is hard to determine。

4。 We’;re still not sure how many volcanoes there are in the***rld, but geologists identified about 1300 active volcanoes, not counting underwater volcanoes。

5。 The biggest volcano on Earth is Hawaii’;s Mauna Kea。 At 33,500 feet (10,210 meters) it’;s even taller than the Everest, but most of it is underwater, so its height relative to sea level is lower。 However…;

6。 The tallest volcano in the solar system is on Mars。 Olympus Mons on Mars is a shield volcano with a height of nearly 22 km (16 mi), almost three times higher than Mount Everest。 It was able to grow this big because Mars doesn’;t have active tectonic plates。

Volcanic eruption on Io。 Image credits: NASA/JPL。

7。 Earth isn’;t the most active place in the solar system –; Jupiter’s moon Io is the most volcanic body in the solar system。 Astronomers recently witnessed two huge eruptions, possibly largest than any ever recorded on our planet。

8。 The two most active volcanoes in the world are Etna in Italy and Hawaii’;s Kilauea, depending on how you judge。 Etna has been active in the past 3,500 years, but it’;s still being used for agriculture because its slopes are so fertile。 Kilauea has been in a state of constant eruption since 1993, and more than 90% of its surface is made from young lava。

Image via USGS。

9。 Volcanoes can be scary, but supervolcanoes can be downright terrifying。 St。 Helens, one of the largest eruptions in history spewed up 0。25 cubic kilometers of volcanic material while the last known eruption from the Yellowstone caldera ejected 4000 times more –; 1000 cubic kilometers。

本文源自: AG游戏网站