← Autodidact Archive · Original Dissent · LA Refugee
Thread ID: 10898 | Posts: 4 | Started: 2003-11-03
2003-11-03 03:04 | User Profile
[url]http://volcanoes.usgs.gov/yvo/2003norris.html[/url]
Lot's of things happening here. Maybe going to blow?
Exerpt: What happened in 2003 at Norris? First, Steamboat Geyser erupted twice in the Spring of 2003 on 26 March and 27 April. Steamboat erupted twice in 2002 and once in 2000 following a nine-year hiatus. This is highly unusual for this "world's largest geyser" that on average only erupts only about every 10 years. The geyser has not erupted since April, but continues to display small geysering events.
On 10 March 2003, a new thermal feature was reported west of Nymph Lake, located about 3.5 km northwest of the Norris Museum. A linear series of vigorous fumaroles about 75 m long had formed in a forested area located about 200 m from the lake's west shoreline on the side of a hill. Fine particles of rock and mineral fragments ejected from the fumaroles coated nearby vegetation. Fumarole temperatures were as high as 92ðC (198ðF), the boiling temperature of water at that elevation. After two months, somewhat reduced steam emission was accompanied by discharge of approximately 11 to 38 liters (3 to 10 gallons) per minute of near-neutral thermal water. Trees within 4 m of the lineament had died and were being slowly combusted.
Then, beginning July 11, Yellowstone National Park staff began noticing several changes in the Back Basin at Norris. (See the Yellowstone National Park interactive map of the Norris Geyser Basin for geyser locations.)
Porkchop Geyser, which sprang to life from a small hot spring in 1971, erupted on July 16, 2003 for the first time since 1989. The temperature of waters in Porkchop's vent increased continuously from 67ðC (152ðF) in early April to 88ðC (190ðF) in early July. Also, water drained away or was boiled to dryness at several active geysers, resulting in hissing steam vents (for example, Pearl Geyser). Still other geysers have erupted more frequently and regularly, while some thermal features that usually release hot water and steam now send steam jetting into the air.
Porkchop Geyser
2003-11-03 03:09 | User Profile
When the Yellowstone caldera blows say bye bye USA. :furious:
2003-11-04 00:39 | User Profile
I heard that all of Yellowstone is a Supervolcano. It's on a 125,000 year cycle, or therabouts. One blew up in the Pacific about 150,000 years ago, and was said to be the loudest noise ever heard by human ears. In addition to being very loud, it also almost closed us out as a species, what with the nuclear winter and massive dieoff.
Ausonius
Added later:
[QUOTE]A supervolcano is an enormous volcano that is an order of magnitude larger than ordinary volcanoes. A supervolcano occurs when a huge magma chamber in the Earth's crust erupts after being under great pressure, causing a large caldera to form as the land over the magma chamber collaspses. This type of eruption is probably able to cause a major climate change and a mass extinction as it ejects dust, debris, and caustic gases into the atmosphere. Supervolcanos do not look like the familiar cone-shaped volcano - a supervolcano looks like a huge collapsed crater. Yellowstone National Park (in Wyoming and Montana, USA) is a supervolcano70 km long and 30 km wide; it is due to erupt soon (in terms of geological time). [/QUOTE]
[QUOTE]3 February 2000
Scientists warn of supervolcano that could blot out the Sun and bring a global winter
By Steve Connor, Science Editor
Geologists will warn MPs today of the threat posed by a supervolcanic eruption that could devastate the global climate, disrupt agriculture and cause severe food shortages.
Senior members of the Geological Society are to give evidence to the House of Commons Science and Technology Committee, claiming that a massive eruption could emit enough gas, dust and debris into the atmosphere to block out sunlight and cause a global "volcanic winter".
"Given the climatic impact of volcanic eruptions ... and the likelihood of future eruptions, the society recommends that the committee investigate the extent to which the Government has explored the agricultural, economic and political consequences of volcanic winters," the Geological Society says in its written submission.
Geologists are particularly concerned about so-called "supervolcanoes", which can erupt with a force powerful enough to eject thousands of cubic kilometres of debris and hundreds of thousands of tons of sulphuric acid, which can form a reflective shield, cutting out sunlight.
Historical records of eruptions big enough to have a global effect show they are more common than many people imagine and have had a serious impact on human existence.
"For example, a powerful eruption of the Indonesian volcano Tambora in 1815 was followed by one to two years of unusually cold climate around the world," the society says. "In Europe, annual mean temperatures were 1ðC to 2.5ðC lower than normal, harvests were late or failed altogether, grain prices were at their highest and famine was widespread."
Tambora measured seven on the eight-point volcanic explosion index. The explosion in 1991 of Mount Pinatubo in the Philippines was 10 times smaller, registering six points on the index, which was 10 times bigger than the five-point explosion in 1980 of Mount St Helens in the United States.
Bill McGuire, professor of geohazards at University College London and a member of the society's board, said many supervolcanoes are not typical hill-shaped structures but huge, collapsed craters called calderas that are filled with hot magma and are harder to detect. One potentially dangerous supervolcano exists under Yellowstone National Park in the United States and was only detected in the Sixties when infra-red satellite photographs revealed a magma-filled caldera 70km long and 30km wide.
The Yellowstone supervolcano has erupted regularly over the past 2 million years at intervals of about 600,000 years. The last time was about 640,000 years ago, making another eruption "imminent" in geological time.
A Horizon documentary to be broadcast tonight on BBC2 reveals that one of the biggest eruptions, 74,000 years ago at Toba in Sumatra, may have pushed man to the brink of extinction. Toba, which is estimated to have been a maximum eight-point explosion, caused a volcanic winter lasting several years and reduced the population to a few thousand, resulting in a genetic "bottleneck" that can be observed in our genes today.
"There's nowhere to hide from the effects of a supervolcano. When one goes off it will be like a nuclear winter without the radiation," Professor McGuire said. [/QUOTE]
Looks like my dates were a bit off. Facts right, times wrong. So much for getting 4 hours of sleep a night.
Ausonius
2003-11-07 23:35 | User Profile
[QUOTE]When the Yellowstone caldera blows say bye bye USA[/QUOTE]
The eruption would blot out much of the Midwest. More importantly, you can also say bye-bye to photosynthesis the world over, for a year or two at least.