Earth's+Dynamic+Surface

**Earth's Dynamic Surface... Volcanoes, Earthquakes, Canyons, etc.**

__**Hydrothermal Vents**__

Deeps sea vents on the ocean floor that spew water that is over 700 degress f. Life is also found here, they live through a process called chemosynthesis. More is explained in this video and the video on the left: The animals described in both videos are really big, tube worms can grow up to 3 meters and clams can be 1 foot long or larger.

A Video on Hydrothermal Vents (intro):

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A Second Video (more detail): media type="youtube" key="4LoiInUoRMQ?version=3" height="360" width="640"

__**Earthquakes**__

I found this vid that describes the basics of earthquakes, and how they can be good or bad... the guy also has an awesome novembeard.... [] media type="youtube" key="-zNyVPsj8zc?version=3" height="360" width="640" (On YouTube, you can right click the video and select 'Copy Embed URL', then click 'Widget' on the Wiki page editing bar, click 'Video', then 'YouTube', and then copy the URL into the box. Then it shows up here, which is sweet. Mr. L.,)

Definition: //n.// A sudden movement of the earth's crust caused by the release of stress accumulated along geologic faults or by volcanic activity

= Death toll in second Turkish quake rises to 40 =

ISTANBUL | Sun Nov 13, 2011 7:35am EST (Reuters) - Last week's earthquake in southeast Turkey killed 40 people, bringing the death toll in two tremors over the last three weeks to 644, the state Disaster and Emergency Administration (AFAD) said on Sunday.

Tens of thousands of people have been left homeless by the quakes in Van province, and their plight has been worsened by freezing temperatures after the first heavy snowfall of winter.

Prime Minister Tayyip Erdogan visited the quake zone on Saturday amid rising anger among homeless families over relief efforts. Few people are willing to stay in homes scarred by cracks in walls and ceilings while aftershocks shake the area.

Mechanical diggers on Sunday were clearing away rubble from a demolished hotel, television pictures showed. The death toll had stood at 33 on Saturday afternoon.

Under an aid campaign launched by Erdogan, a total of 132 million lira ($74 million) has been raised, including $50 million sent by Saudi Arabia, AFAD said on its website.

It said 30 people had been rescued alive from the rubble since the 5.7 magnitude quake on November 9. Out of 25 buildings that collapsed, only two were occupied -- both hotels -- as most people had left their homes after a far bigger quake on October 23.

A total of 222 people were rescued after the first earthquake, AFAD said. It said some 70,000 tents and 330,000 blankets have been sent to the region.

Funerals were being held on Sunday for two journalists from Dogan news agency who had been staying at the Bayram Hotel to cover the aftermath of the 7.2 magnitude quake that struck Van.

On Saturday, Erdogan promised permanent housing would be provided for the majority of those needing new homes by August next year, before pleading with people to enter tent camps established to see them through the winter.

Police had fired tear gas to break up a protest in Van on Thursday by some 200 men angered by the way tents had been distributed and calling for the local governor's resignation.

The government is sensitive to criticism, particularly as Van is a mainly Kurdish region. Turkey is fighting a long-running Kurdish separatist insurgency, but Erdogan has sought to reach out to ordinary Kurds with cultural reforms.

Authorities have established tent cities, where sanitation and relief are more easily provided, but many families complain they have no tents and are left fending for themselves. ($1 = 1.775 Turkish Liras)

__Arial view of Earth timelapse__
 Earth | Time Lapse View from Space, Fly Over | NASA, ISS from Michael König on Vimeo.

__**Volcanoes**__

__How Valcanoes Are Formed__
The formation of volcanoes explained in geological terms: an animation depicts Iceland on the mid-Atlantic ridge, a great fault lying between the Americas and Africa; the Earth's surface is divided into plates; the plates move across the Earths surface causing continental drift; an animation shows a cross-section of the Earth, each layer is described and named, the theory of plate tectonics is introduced; an animation demonstrates the constructive and destructive elements of plate tectonics and how volcanoes are formed along plate boundaries; an animation of 'hot spot' volcanoes forming on the Pacific plate, Mount Kilauea, Hawaii being a good example.

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- Caitlyn

__Types of Volcanoes:__
====**Stratovolcanoes** are tall volcanoes composed of layers of lava, ash, and cinders. Cinders and ash pile up and then the lava flows over it, and cools down, thus creating another layer, and the process continues. They are characterized by their steepness and periodic, explosive eruptions. The magma that forms this lava is often felsic, rather than mafic. Meaning the magma is enriched with the lighter minerals such as potassium, silicon, oxygen, aluminum, and sodium. Stratovolcanoes are common around subducion zones, they form along plate tectonic boundaries where oceanic crust is pushed under the continental crust, or another oceanic plate.==== ====**Supervolcanoes** are the most dangerous of all the types of volcanoes. They are capable of producing an eruption that covers an area of 1,000 cubic kilometers, or 240 cubic miles. They are extreemely dangerous because after one erupts, it can create severe cooling of global temperatures for years after because of the huge volumes of ash and sulfur erupted. Supervolcanoes can occur when magma from the Earth rises into the crust but is unable to break through. Pressure builds up in a large magma pool until the crust is unable to contain the pressure. There are currently six known Supervolcanoes.==== ====**Submarine Volcanoes** are found on the ocean floor. In shallow water they can blast steam and rocks high above the surface of the water. Other volcanoes lie at such great depths so that the weight of the water prevents them from releasing the steam and gases. They may become so large as to break through the surface of the water, creating a new island. Submarine Volcanoes are estimated to account for 75% of annual magma output. They are mostly located near areas of tectonic plate movement, know as ocean ridges.==== ====**Subglacial Volcanoes** develop underneath ice caps. They are made up of flat lava which flows at the top of extensive pillow lavas and palagonite. Palagonite is a substance that forms from the interaction between water and volcanic glass. When the icecap melts, the lavas on top collapse, and the result is a flat-topped mountain.====

__Why Do Volcanoes Erupt? __  Deep within Earth it's so hot that some rocks slowly melt and become a thick flowing substance called magma. Because it's lighter than the solid rock around it, magma rises and collects in magma chambers. Eventually some of the magma pushes through vents and fissures in Earth's surface. A volcanic eruption occurs. Magma that has erupted is called lava.

__Volcanic Eruptions __  Some volcanic eruptions are explosive while others are not. How explosive an eruption is depends on how runny or sticky the magma is. If the magma is thin and runny, gases can easily escape from it. When this type of magma erupts, it flows out of the volcano. Lava flows rarely kill people, because they move slowly enough for people to get out of their way. Lava flows, however, can cause considerable destruction to buildings in their path.  If magma is thick and sticky, gases cannot easily escape. Pressure builds up until the gases escape violently and explode. In this type of eruption, the magma blasts into the air and breaks apart into pieces called tephra. Tephra can range in size from tiny particles of ash to house-size boulders. Explosive volcanic eruptions can be dangerous and fatal. They can blast out clouds of hot tephra from the side or top of a volcano. The fiery clouds race down mountainsides destroying almost everything in their path. Ash erupted into the sky falls back to Earth like black, powdery snow, but snow that won't melt. If thick enough, blankets of ash can suffocate plants, animals, and humans. ~joanelle:)

Volcano Erupting: On 2 November, [|OVDAS] - [|SERNAGEOMIN] reported that the Alert Level for Cerro Hudson was lowered to Yellow, Level 4, noting that the eruption that began on 26 October had ceased. [|ONEMI] reported that the 140 evacuees were permitted to return home. Analysis of [|ash] deposited on the edge of the crater during the eruption indicated the presence of juvenile basalt. During 1-6 November between 16 and 110 earthquakes per day were recorded and satellite images showed drifting plumes daily.

__Geologic Summary:__ The ice-filled, 10-km-wide of the remote Cerro Hudson volcano was not recognized until its first 20th-century eruption in 1971. Cerro Hudson is the southernmost volcano in the Chilean Andes related to subduction of the Nazca plate beneath the South American plate. The massive, 1905-m-high Cerro Hudson covers an area of 300 sq km. The compound caldera is drained through a breach on its NW rim, which has been the source of mudflows down the Río de Los Huemeles. Two cinder cones occur north of the volcano and others occupy the SW and SE flanks. Hudson has been the source of several major explosive eruptions. An eruption about 6700 years ago was one of the largest known in the southern Andes during the Holocene; another eruption about 3600 years ago also produced more than 10 cu km of tephra. An eruption in 1991 was Chile's second largest of the 20th century and formed a new 800-m-wide crater in the SW part of the caldera.

<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: medium; text-align: left;">[|Map] <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: medium; text-align: left;">[|Holocene] <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: medium; text-align: left;">[|caldera]

<span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: medium; text-align: left;">Sources:

1. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: medium; text-align: left;">[|Servicio Nacional de Geología y Minería (SERNAGEOMIN)]

2. <span style="display: block; font-family: Arial,Helvetica,sans-serif; font-size: medium; text-align: left;">[|Oficina Nacional de Emergencia - Ministerio del Interior (ONEMI)]

- Annie

Volcano Erupting Underwater:
I looked at one of the links on The Great Links page and found this video on a volcano erupting underwater! Check it out!!!!

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-Julia

__**Volcano Behind Atlantis Legend Re-awakens**__ Main Idea: The violent volcanic eruptions at the Greek isle of Santorini about 3,600 years ago spewed forth over 10 cubic miles of lava, devastating the the ancient seafaring Minoan civilization and inspiring the legend of the lost city of Atlantis. The resulting volcanic crater appears as a small cluster within the larger collection of Greek islands in the Aegean Sea. Over the next four millennia, the largely underwater caldera at Santorini has experienced a series of smaller eruptions, ending most recently in 1950. Santorini awakened in January 2011 with a swarm of tremors, each magnitude 3.2 or less, GPS research has revealed.

Full Story At>>>> []

~Joanelle:) (and I know the article is pretty old but I thought it was cool anyway)

__**Other**__ __<span style="background-color: #ffffff; color: #7de8e8; font-family: Verdana,Geneva,sans-serif; font-size: 130%;">Hot Springs! __ <span style="color: #000000; font-family: Verdana,Geneva,sans-serif; font-size: 110%;">*Definition* : A thermal spring having water warmer than 37°C (98°F). The water is usually heated by emanation from or passage near hot or molten rock. <span style="font-family: Verdana,Geneva,sans-serif; font-size: 110%;"> *Why is the water hot?* : The water coming from a hot spring is heated by geothermal heat (heat from Earth's mantle). The temperature of rocks inside of the earth increases with depth. If water percolates deep enough into the crust then it will be heated as it comes into contact with hot rocks. This is how the water from hot springs in non-volcanic areas is heated. <span style="font-family: Verdana,Geneva,sans-serif; font-size: 110%;">*Therapeutic uses of hot springs* : Since heated water can contain more dissolved solids, hot springs often have a high mineral content. They can contain calcium, lithium and radium. They are often locations for rehabilitation clinics for people with disabilities.

<span style="color: #7de8e8; font-family: Verdana,Geneva,sans-serif; font-size: 130%;">__G____eysers!__ <span style="font-family: Verdana,Geneva,sans-serif; font-size: 110%;">*Definition* : A hot spring that intermittently sends up fountainlike jets of water and steam into the air. <span style="font-family: Verdana,Geneva,sans-serif; font-size: 110%;">*How does a geyser work?* : The formation of geysers is due to three specific geologic conditions (intense heat, water and a plumbing system). Geysers are located near active volcanic areas, and their spewing of water is due to the proximity of magma. What happens is, surface water percolates down to an average depth of around 2,000 metres (6,600 ft) where it makes contact with hot rocks. This causes the pressurized water to boil, which results in the geyser spraying out hot water and steam out of its surface vent. <span style="font-family: Verdana,Geneva,sans-serif; font-size: 110%;">*Types of geysers* : Fountain geysers and cone geysers. Fountain geysers erupt from pools of water. The eruptions occur in even, intense and sometimes violent bursts. Cone geysers erupt from cones (hence the name) or mounds of geyserite. The eruptions usually occur in even, steady jets. They can last from a couple seconds to several minutes. ~joanelle:)