What is a volcano? Introduction to volcanoes The earth's mountains, plains, plateaus, soils, rocks, etc. as we see it today is believed to have gone through many phases, with about 80% of it being carved out by the action of volcanoes. A volcano is simply a rapture (opening or vent) on the earth's surface (crust) through which molten magma (extremely hot mixture of gases, lava, ash and other burning substances) escape on to the earth's surface. How do Volcanoes look like? In May 1980, the Mountain St. Volcanoes occur at weak zones or points in the earth’s crust (including constructive and destructive boundaries). For history lovers… In A.D. 79 (really long ago) two Roman cities, Pompeii and Herculaneum, were completely buried in ash and dust in a matter of hours after a volcanic eruption. The word, ‘volcano’ was made out of the name of a Roman god of a small island in the Mediterranean sea of Sicily called ‘Volcan’. Now we shall see in a bit more detail how volcanoes come about.
How many oceans are there? While there is only one global ocean, the vast body of water that covers 71 percent of the Earth is geographically divided into distinct named regions. The boundaries between these regions have evolved over time for a variety of historical, cultural, geographical, and scientific reasons. Historically, there are four named oceans: the Atlantic, Pacific, Indian, and Arctic. However, most countries - including the United States - now recognize the Southern (Antarctic) as the fifth ocean. The Pacific, Atlantic, and Indian are known as the three major oceans. The Southern Ocean is the 'newest' named ocean.
Types of Volcanic Eruptions Volcanic Eruptions The most common type of volcanic eruption occurs when magma (the term for lava when it is below the Earth's surface) is released from a volcanic vent. Eruptions can be effusive, where lava flows like a thick, sticky liquid, or explosive, where fragmented lava explodes out of a vent. In explosive eruptions, the fragmented rock may be accompanied by ash and gases; in effusive eruptions, degassing is common but ash is usually not. Volcanologists classify eruptions into several different types. Hawaiian Eruption In a Hawaiian eruption, fluid basaltic lava is thrown into the air in jets from a vent or line of vents (a fissure) at the summit or on the flank of a volcano. Hawaiian eruptions get their names from the Kilauea volcano on the Big Island of Hawaii, which is famous for producing spectacular fire fountains. Strombolian Eruption Strombolian eruptions are distinct bursts of fluid lava (usually basalt or basaltic andesite) from the mouth of a magma-filled summit conduit.
Quiz Whiz: Volcanoes Back Next Quiz Whiz: What's on the Menu? Previous Quiz Whiz: The Moon Games Quiz Whiz: Volcanoes See how much you know about explosive mountains known as volcanoes. More Games African Animals Maze Game Quick Play Arctic Animal Memory Action Arctic Fox Snowboarding Animals Beaver Badminton Dive Deeper Hurricanes 101 - Ep. 3 More Freaky Forces of Nature Auroras, Snow Rollers, and Other Freakiness! Earthquake Lightning Tornado Many cave-dwelling fish don’t have eyes. More Curious Facts Volcanoes 101 - Ep. 13 More Giant's Causeway - Ep. 12 More Tornadoes 101 - Ep. 2 Hurricane Dolphin Diving x Show Link
Types of Volcanoes & Eruptions / Volcanoes / Science Topics / Learning / Home - GNS Science Volcanic Fields Volcanic fields, such as Auckland and Northland, are where small eruptions occur over a wide geographic area, and are spaced over long periods of time (thousands of years). Each eruption builds a new single new volcano, which does not erupt again. Mount Eden and Rangitoto Island are examples in Auckland. Cone Volcanoes Cone volcanoes (also called composite cone or stratovolcanoes) such as Ruapehu, Taranaki / Egmont and Ngauruhoe, are characterised by a succession of small-moderate eruptions from one location. The products from the successive eruptions over thousands of years build the cones. Caldera Volcanoes Caldera volcanoes, such as Taupo and Okataina (which includes Mt Tarawera), have a history of infrequent but moderate-large eruptions. Multiple types of eruptions can occur at each of New Zealand’s volcanoes - the eruption type can vary minute to minute. Hydrothermal eruptionAn eruption driven by the heat in a hydrothermal systems.
Mountain Ranges of the World Mountain Ranges of the World There are many different mountain ranges in the world, each with its own unique shapes and characteristics. Below are some of the more famous from around the world. The Alps The Andes The Himalaya The Rockies The Appalachians The Rwenzori The Pyrenees The Alborz The Atlas The Urals The Sierra Nevada The Cascades The Alaska Range The Great Dividing Range The Zagros The Karakoram The Hindu Kush The Brooks Range Check out our new Photos page to purchase museum-quality photosby Mountainprofessor.com!
Volcano Safety Tips | Volcano Preparedness Mudflows are powerful “rivers” of mud that can move 20 to 40 mph. Hot ash or lava from a volcanic eruption can rapidly melt snow and ice at the summit of a volcano. The melt water quickly mixes with falling ash, with soil cover on lower slopes, and with debris in its path. This turbulent mixture is dangerous in stream channels and can travel more than 50 miles away from a volcano. Intense rainfall can also erode fresh volcanic deposits to form large mudflows. If you see the water level of a stream begin to rise, quickly move to high ground. Stay out of the area defined as a restricted zone by government officials.
Quick Facts on Icebergs | National Snow and Ice Data Center Icebergs are commonly found near Antarctica and in the North Atlantic Ocean near Greenland. What is an iceberg? Icebergs are pieces of ice that formed on land and float in an ocean or lake. Icebergs come in all shapes and sizes, from ice-cube-sized chunks to ice islands the size of a small country. The term "iceberg" refers to chunks of ice larger than 5 meters (16 feet) across. How do icebergs form, and where do they go? Icebergs form when chunks of ice calve, or break off, from glaciers, ice shelves, or a larger iceberg. When an iceberg reaches warm waters, the new climate attacks it from all sides. Icebergs can develop into a variety of shapes as they break apart. Why are icebergs important? Icebergs pose a danger to ships traversing the North Atlantic and the waters around Antarctica. The International Ice Patrol uses airplanes and radars to track icebergs that float into major shipping lanes. Scientists test their equipment on a small iceberg during the 2006 IceTrek expedition.
Volcano Safety Tips, Volcano Preparation, Volcano Readiness A volcanic eruption can be an awesome and destructive event. Here are some tips on how to avoid danger and what to do if you're caught near an eruption. Safety Tips • Stay away from active volcanoes. • If you live near an active volcano, keep goggles and a mask in an emergency kit, along with a flashlight and a working, battery-operated radio. • Know your evacuation route. If a Volcano Erupts in Your Area • Evacuate only as recommended by authorities to stay clear of lava, mud flows, and flying rocks and debris. • Avoid river areas and low-lying regions. • Before you leave the house, change into long-sleeved shirts and long pants and use goggles or eyeglasses, not contacts. • If you are not evacuating, close windows and doors and block chimneys and other vents, to prevent ash from coming into the house. • Be aware that ash may put excess weight on your roof and need to be swept away. • Ash can damage engines and metal parts, so avoid driving.