explainxkcd.com/wiki/index.php/2344:_26-Second_Pulse
Source: xkcd.com
A natural needle
Is it the dark tower, an ancient skyscraper, a giant finger, the tower of Mordor or a monolith? Although it looks like the perfect setting for a fantasy trilogy, this place is for real. Pico Cão Grande (a.k.a. the great dog peak, the reason behind this is unclear) is a volcanic landform known as a volcanic plug or needle on the island of São Tomé in the Gulf of Guinea off the coast of Africa. A volcanic plug is created when magma hardens in a volcanic vent and is trapped. With active volcanoes plugs can cause extreme built up of pressure leading to a very explosive eruption. However, if this does not happen erosion removes the surrounding rock and only the plug of lava is exposed. Pico Cão Grande rises a mere 300m, its peak is 663m high. Nearby another volcanic plug called Pico Cão Pequeno, as the name suggests, is not as high or impressive. The plug is very difficult to climb due to the thick blanket of mist that usually surrounds it. Rainfall varies between 4500-500mm a year on São Tomé making it a very wet and misty place. In addition, moss, lianas and giant ferns cover the needle making it as slippery as glass. To top this, the ragged spine is inhabited by vicious snakes.
-OW-
Image: Copyright Pedro Caleiro. Pico Cão Grande appears as something out of a fantasy story.
Source: facebook.com
A natural needle
Is it the dark tower, an ancient skyscraper, a giant finger, the tower of Mordor or a monolith? Although it looks like the perfect setting for a fantasy trilogy, this place is for real. Pico Cão Grande (a.k.a. the great dog peak, the reason behind this is unclear) is a volcanic landform known as a volcanic plug or needle on the island of São Tomé in the Gulf of Guinea off the coast of Africa. A volcanic plug is created when magma hardens in a volcanic vent and is trapped. With active volcanoes plugs can cause extreme built up of pressure leading to a very explosive eruption. However, if this does not happen erosion removes the surrounding rock and only the plug of lava is exposed. Pico Cão Grande rises a mere 300m, its peak is 663m high. Nearby another volcanic plug called Pico Cão Pequeno, as the name suggests, is not as high or impressive.
The plug is very difficult to climb due to the thick blanket of mist that usually surrounds it. Rainfall varies between 4500-500mm a year on São Tomé making it a very wet and misty place. In addition, moss, lianas and giant ferns cover the needle making it as slippery as glass. To top this, the ragged spine is inhabited by vicious snakes.
-OW-
Image: Copyright Pedro Caleiro. Pico Cão Grande appears as something out of a fantasy story.