Why the Lost Lake in Oregon disappears every year

The lost lake, located in the forest reserve "Mount Hood" (Oregon), is a real mystery of nature. In the winter season it looks the same as any other large array of fresh water. But when it gets drier and warmer, the water disappears, and a 85-acre lake turns into a picturesque meadow. It turns out that there is a scientific explanation for this natural magic: the water simply flows into an underground tunnel formed in ancient times by a stream of lava.

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Jude McHugh, spokesman for the Willamette National Forest Reserve in Oregon, says that the Lost Lake begins to fill in the fall, during the rainy season. Precipitation at this time falls a lot, and the lava tunnel has a diameter of only about 2 meters, so immediately all the water does not have time to leave the lake. Thus, it seems that the lake, whose depth, by the way, is about 50 meters, remains filled, although some water constantly flows into the tunnel. This continues in the spring season, when snow melts in the mountains. But as soon as external sources (precipitation and thawed waters) cease to feed the pond, the lava pipe does its work, and the Lost Lake disappears.

Scientists still can not say exactly where the water goes. There is a hypothesis that water seeps through a porous volcanic rock, and then enters the groundwater system. Cascade mountains - a range of ancient volcanoes and high mountains - stretched across the state of Oregon, so here lava tunnels - this is the most common thing. But none of them can be called as impressive as the one that is located under the Lost Lake.

How are lava tunnels formed?

Such tunnels are formed when a lava from several channels flows into one large stream, just as numerous streams merge into a large river. In the process, lava can spill over the surface of the earth and begin to solidify. Thus, on both sides of the flow, strong walls of solidified magma are formed. The lava continues to flow, which is accompanied by soil erosion. As a result, the depth of the channel increases. Eventually a crust forms above the channel - a kind of tunnel vault. And this tunnel retains its outlines for a long time after the molten rock ceased to flow through it.

Variety of shapes and sizes of lava tunnels

Lava tunnels can be different in size. Some of them reach only 30 cm in diameter, while others are so spacious that they can straighten up in full growth. It is not surprising that adventurers and thrill seekers are very fond of traveling through such tunnels. The longest and deepest canals can be seen in the Hawaiian Volcanic National Reserve, where there are 2 active volcanoes: Kilauea (one of the most active volcanoes in the world) and Mauna Loa (one of the largest volcanoes in the world, formed above the surface of the earth).