There are events that take place throughout the history of the world that are so massive that they are ingrained in our heads from the moment that we hear of them. The places in which those events took place become a tourist spot for many people to visit but at one point they were the site of disaster. One such place is Yellowstone Park. The site where many people in the US visit every year as one of the national parks in the country is also the site of the Yellowstone Volcano. This is what is called a supervolcano which means that its eruptions have been categorized as a VEI8 (volcano eruption index).

Yellowstone Plateau

There are three calderas in the Yellowstone Plateau. The first one is the Henry’s Fork Caldera which is located in Idaho and it was formed 1.3 million years ago. The Island Park Caldera is oval shaped and it is much larger. It extends very much into the Yellowstone National Park. The Yellowstone Caldera can also be found within the park but the only one to be visible currently is the Henry’s Fork Caldera. The Island Park Caldera is much older than Henry’s Fork and its dimensions are close to 80 by 65 km. That should give you an idea of how big a Yellowstone Volcano explosion could be.

Previous Eruptions

The Yellowstone Volcano has erupted in the past and it will erupt again. It has been calculated that this supervolcano erupts every 600,000 years with the last recorded eruption happening 640,000 years ago. Today there have been four recorded VEI8 eruptions recorded at Yellowstone, with the oldest taking place 2 million years ago and the most recent one 640,000 years ago.

Where Will The Eruption Take Place?

The massive size of the Yellowstone Volcano means that there are different areas where the next eruption could take place. More than likely an eruption of the Yellowstone Volcano would be centered in a parallel fault zone out of three possibilities. The two areas with the largest flow of lava are always a possibility but in recent years a third area has been displaying frequent tremors. Because scientists know these areas they can monitor them closely. While the massive eruptions don’t take place often, small ones do take place a lot more frequently but they are not of the explosive kind.

What Happens When The Yellowstone Volcano Erupts?

The Yellowstone Volcano is known to be a supervolcano because in the past (2 million years ago) it released over 600 cubic miles of lava and ash in one single event.
en the last eruption took place about 640,000 years ago it is believed that it caused the last ice age. The reason the ice age took place after the eruption is that the ash went up to the atmosphere blocking a lot of the heat the planet receives from the sun. That led to many species dying because vegetation could not survive and therefore animals had no food. Another supervolcano explosion which happened in Indonesia about 74,000 years ago is believed to have killed close to 60% of the human population.

What Would Happen Today?

If the Yellowstone Volcano were to erupt today the consequences could be even greater than the Sumatra supervolcano which killed close to 60% of the population. The number of people in the world is a little over 7 billion already and if an ice age were triggered and animals and vegetation were to die then even fewer people would be able to survive. Food shortages would take place almost immediately and they would affect people even on the other side of the world. Those who live in the nearby area, especially those in Wyoming and the surrounding states, would stand no chance. The lava would kill most of the people in the area and those unlikely survivors would asphyxiate when they breathe in the ash. In other words, a Yellowstone Volcano eruption could mean the extinction of life on the planet.

What Are The Chances?

Despite the fact that some believe that an eruption at Yellowstone is overdue the chances of seeing an eruption on any given day are very small.
ose chances have been calculated to be less than 1 in 10,000 of it happening in a given year and that is including the smaller eruptions. That is not to say that an eruption will not take place sometime; eventually the volcano in Yellowstone will erupt. Today magma is accumulating and tremors can be felt on the ground at Yellowstone. This serves as a constant reminder that this supervolcano could go off at any time.


Yellowstone Volcano Related Articles


A closer look at the 2017 Maple Creek earthquake swarm
December 10, 2018

In June of 2017, an earthquake swarm began beneath the western edge of Yellowstone National Park, just east of Hebgen Lake. This swarm proved to be one of the more persistent swarms observed in Yellowstone, with the main episode lasting more than 3 months and producing thousands of recorded earthquakes. Most of the earthquakes were very small, but a few were felt in the park, including the largest, a magnitude 4.4 earthquake on June 16, 2017.

But what caused this swarm? Magma moving around in the subsurface? Tectonic faulting? Mole people? Find out in this week’s Yellowstone Caldera Chronicles!

Steamboat Counter
May 14, 2018

Steamboat Geyser, in the Norris Geyser Basin, appears to have entered a phase of more frequent water eruptions, much like it did in the 1960s and early 1980s. Although these eruptions do not have any implications for future volcanic activity at Yellowstone (after all, geysers are supposed to erupt, and most are erratic, like Steamboat), they are nonetheless spectacular, and many people had a chance to see Steamboat in eruption during the summer of 2018.

To keep track of the geysering, we will keep an updated count of Steamboat water eruptions on this page. So far in 2018, Steamboat has erupted 30 times (a new record for a single calendar year!). All times below are local.

  • March 15, 5:37 AM
  • April 19, 4:30 PM
  • April 27, 6:30 AM
  • May 4, 11:50 PM
  • May 13, 3:54 AM
  • May 19, 9:49 PM
  • May 27, 7:33 PM
  • June 4, 9:05 AM
  • June 11, 1:06 AM
  • June 15, 4:55 PM
  • July 6, 1:38 PM
  • July 20, 10:36 PM
  • August 4, 2:10 PM
  • August 22, 11:44 AM
  • August 27, 9:30 PM
  • September 1, 11:21 PM
  • September 7, 10:20 AM
  • September 12, 4:23 AM
  • September 17, 9:38 AM
  • September 24, 5:18 AM
  • September 30, 6:55 PM
  • October 8, 10:25 AM
  • October 15, 2:12 PM
  • October 23, 9:29 PM
  • October 31, 8:22 AM
  • November 7, 4:16 PM
  • November 15, 11:04 AM
  • November 21, 7:10 PM
  • November 28, 8:37 PM
  • December 8, 1:07 AM

Would you like to become a Steamboat watcher? If so, there are three datasets to keep an eye on:

  1. Seismic station YNM, in the Norris museum, is the first indicator of an eruption. The webicorder for the station is located here. Look for a thick seismic trace that lasts 30-60 minutes.
  2. About 90 minutes after eruption, increased discharge can often be seen at the Tantalus stream gage. You can get that information here. Scroll down to the plot «Discharge, cubic feet per second» and look for a spike and subsequent decay, but be careful…precipitation can cause spikes too! Rainfall information is given in another plot on that page.
  3. Each night, temperature data from a sensor in the Steamboat drainage channel is downloaded and posted on line. A sudden and short-lived (minutes-long) spike in temperature indicates a Steamboat eruption. To view those data, go to the YVO monitoring map and zoom in on the Norris area. Hover over any of the thermometer symbols to see their names, and click on the one labeled «Steamboat» to see data from various time periods past.

Have fun! You might also check out the Steamboat page at for information about Steamboat activity.


Volcanoes at Yellowstone?

Yellowstone National Park is world-famous for its geysers and hot springs. Those thermal features are easy-to-observe evidence of an active magma system beneath the Park. This magma system has produced some of the largest volcanic eruptions in Earth’s history — eruptions so large that they have been called «supervolcanoes.» One of these eruptions produced a caldera that is about 50 miles across.

Should you be concerned about this? Here are three facts… 1) the most recent super eruption occurred about 640,000 years ago; 2) scientists monitoring the activity at Yellowstone today say «nothing unusual is happening right now»; and, 3) a gigantic eruption is expected to be preceded by significant warnings.

What is a Supervolcano?

A supervolcano is an eruption that rates a magnitude of 8 on the Volcanic Explosivity Index. The VEI is a scale that rates eruptions on their ejecta volume, plume height and duration. The scale ranges from 0 through 8. Only a few dozen eruptions in all of Earth’s history are known to have a VEI of 8. Two of those eruptions, the Lava Creek eruption (640,000 years ago) and the Huckleberry Ridge eruption (2.2 million years ago), occurred at Yellowstone. These eruptions were given the VEI rating because their ejecta volume exceeded 1000 cubic kilometers!

How Active is the Yellowstone Volcano?

The Yellowstone Volcano Observatory closely monitors earthquake activity, ground deformation, streamflow and stream temperatures in the Yellowstone area. Occasional earthquake swarms occur, the ground surface changes elevation and streams change in both discharge amount and temperature. They have no evidence to suggest that a volcanic eruption of any size will happen at Yellowstone in the foreseeable future.

When Was the Last Yellowstone Eruption?

The most recent volcanic eruption at Yellowstone occurred about 70,000 years ago and produced the lava flows of the Pitchstone Plateau. The lava flows of this eruption covered an area about the size of Washington, D.C. and are up to 100 feet thick.

What Causes This Volcanic Activity?

There is a hot spot beneath Yellowstone. A hot spot is a persistent plume of hot material rising through Earth’s mantle. This rising plume delivers heat to the area, causes forces in the crust that produce earthquakes and rarely produces a volcanic eruption. A hotspot is also responsible for the volcanic eruptions of Hawaii.

What Causes the Geysers?

The magmatic activity below Yellowstone causes rock beneath the Park to be much hotter than subsurface rock in other areas. Water that falls as rain or snow above these rocks can infiltrate into the ground and enter the groundwater system. Some of this water encounters the hot rock below and is heated to well above the boiling point. This water remains a liquid because it is under the enormous pressure caused by the weight of the overlying rock. The result is a «superheated» water which can reach temperatures of up to 400 degrees Fahrenheit.

The superheated water is less dense then the cooler water above it. The less dense, superheated water is thus buoyant. This instability causes the superheated water to rise towards the surface through pore spaces in the overlying rock. Some of it will find its way into the cavities that feed the geyser system and be blasted back to the surface in an eruption.

Learn More!

Watch the three USGS videos in the right column. In these videos, Jake Lowenstern, Scientist in Charge of the Yellowstone Volcano Observatory, will teach you about the supereruptions at Yellowstone, how they are being monitored and what is expected in the future.