Search results
Results from the WOW.Com Content Network
[5] [6] [7] At 37.9 km (23.5 miles), it has the longest underwater section of any tunnel in the world and is the third-longest railway tunnel in the world. The speed limit for trains through the tunnel is 160 km/h (99 mph). [8] The tunnel is owned and operated by Getlink, formerly Groupe Eurotunnel.
A list of active and extinct submarine volcanoes and seamounts located under the world's oceans. There are estimated to be 40,000 to 55,000 seamounts in the global oceans. [1] Almost all are not well-mapped and many may not have been identified at all. Most are unnamed and unexplored.
The shell is of a unique construction, with three layers; the outer layer consists of iron sulphides, the middle layer is equivalent to the organic periostracum found in other gastropods, and the innermost layer is made of aragonite. The foot is also unusual, being armored at the sides with iron-mineralised sclerites.
Submarine volcanoes are underwater vents or fissures in the Earth's surface from which magma can erupt. Many submarine volcanoes are located near areas of tectonic plate formation, known as mid-ocean ridges. The volcanoes at mid-ocean ridges alone are estimated to account for 75% of the magma output on Earth. [1]
The oldest underwater rail tunnel in the world, crossing the Mersey in Liverpool: 1.21 km: 1881–1886 Severn Tunnel: Wales – England: One of the oldest underwater rail tunnels in the world: 7.01 km: 1873–1886 Blackwall Tunnel (western) London, England: The oldest underwater vehicular tunnel in the world, crossing the Thames in London: 1.35 ...
Submarine eruptions are volcano eruptions which take place beneath the surface of water. These occur at constructive margins, subduction zones and within tectonic plates due to hotspots. This eruption style is far more prevalent than subaerial activity.
A seamount is an underwater volcano; Davidson rises 7,480 ft (2,280 m) above the surrounding ocean floor. Although there are over 30,000 seamounts in the Pacific Ocean alone, only about 0.1% of them have been explored. [4] The aqueous environment of the seamount means that it behaves differently from volcanoes on land.
Made of cast iron, it was known as Wilson's Patented Stone-Cutting Machine, after inventor Charles Wilson. [16] It drilled 3 meters (10 ft) into the rock before breaking down (the tunnel was eventually completed more than 20 years later, and as with the Fréjus Rail Tunnel, by using less ambitious methods). [17]