Super Volcanoes
Eruptions vary in the material quantity released, their type (effusive/explosive) and duration. Thus, it's difficult to compare one eruption with another. Two key factors need to be considered...
1. Magnitude - quantity of material erupted. 2. Intensity - the speed at which material is erupted.
Yellowstone is understood to erupt roughly every...
630,000 years and many fear it is overdue an eruption.
In assessing the explosivity of an eruption, several factors are considered, what are they?
> volume of erupted material, > the height ejected material reaches, > duration (in hours) > various qualitative descriptions.
On what evidence do scientists cite in their beliefs that another eruption form Yellowstone could potentially reach areas 500 miles away?
Based on the ash beds, such as those in Lava Creek and Hucklebrry Ridge, thought to have been indirectly created by previous Yellowstone eruptions.
Why isn't it known exactly how often Yellowstone has erupted, nor the volume of material extruded?
Because the evidence of earlier eruptions may have been either buried or destroyed by later ones.
What is believed to have happened during Yellowstone's largest eruptions?
During Yellowstone's largest eruption, 2 million years ago, ash was spewed out over much of the western half of North America, while gases (such as SO2) and tiny particulates were carried around the globe in the upper atmosphere.
How is the impact of a super volcano eruption deduced?
From the extent and depth of ash layers and their impact on plant, insect and animal species (palaeobiology).
What are Super Volcanoes?
Super Volcano: erupts over 1000km2 of material in a single eruption event. Super-volcanoes exist as giant calderas. The Yellowstone super-volcano in Wyoming has a caldera measuring 75km in diameter.
Measurements have indicated both rises and falls in ground surfaces within Yellowstone's caldera. But what does the latest research suggest?
That volcanoes can display quite rapid ground movements without necessarily erupting.
How much force does Yellowstone have the potential to erupt with?
The magma below Yellowstone National Park is 2 ½ times larger than previously estimated, meaning the park's super volcano has the potential to erupt with a force about 2,000 times the size of Mount St. Helens, according to a new study.
What is Yellowstone's most probable eruption?
The most probable eruption will be a lava flow or a hydrothermal event. These would have little if any impact outside of the Yellowstone region.
What did scientists from the university of Illinois discover about supervolcanoes?
The scientists discovered the effects of tectonic stress play a crucial role in the eruptions of supervolcanoes. The scientists expect precursors to include tens or hundreds of metres of uplift over hundreds of thousands of years before a catastrophic eruption.
How can you assess volcanic activity?
Using the Volcanic Explosive Index (VEI)
Although in terms of magnitude two eruptions can be the same, they may be very different types of volcanic event. The most widely used measure of eruption is the...
Volcanic Explosivity Index (VEI). It combines magnitude and intensity into a number from 0, the least explosive, to 8, the most explosive. Each increase in number represents nearly a ten-fold increase in explosivity.
Where is the Yellowstone Super Volcano?
Yellowstone volcano is one of the world's biggest and most active supervolcanoes, in Wyoming, western United States.
Briefly describe Yellowstone's eruption history.
Yellowstone's volcanic activity began 2 million years ago when a giant caldera formed. 2 further huge eruptions took place 1.3 million and 640,000 years ago. In addition to these, dozens of smaller eruptions have occurred.
Apart from Yellowstone, other super volcanoes that have been active in the past 2 million years include Long Valley in...
eastern California and Toba in Indonesia. The most recent super-volcanic eruption occurred 27 millenia ago at Taupo, North Island, New Zealand.
There's been much speculation concerning eruption events by super-volcanoes and their impacts. Tectonic events don't...
follow a regular pattern, making accurate and reliable predictions impossible.
No evidence exists for growth in a near-surface chamber of the size required for a super-volcanic eruption at Yellowstone. Recent earthquakes are linked to...
fractures in brittle rocks. Even if long-period events are registered, this doesn't mean an eruption is imminent.
A recently published study from the University of Illinois suggests humanity would be given ample time to prepare for a mega blast. According to a...
geology professor, new models of regional-scale tectonic stress could give experts enough time to anticipate a catastrophic eruption. The team of researchers created the new models based on earlier eruptions of the Taupo Volcanic Zone in northern New Zealand.
Given that the hot spot under Yellowstone heats, stretches and weakens the crustal rocks, volcanic activity could...
occur at any time. However, the probability of a super-volcano style eruption is very low.
The VEI is not that useful for eruptions such as those on Hawaii. But, it's valuable in suggesting...
the relative impacts volcanoes might have at different geographical scales.