GRANITE PEAK PUBLICATIONS: Accompanying travelers to the national park since 2002

All posts tagged geologists

Cliff Geyser

Cliff Geyser on Iron Spring Creek

One topic that frequently comes up in the articles and blog posts on YellowstoneTreasures.com is the fact that Yellowstone is on a hot spot, which is the reason for all the wonderful hydrothermal features: geysers, hot springs, mudpots, and fumaroles. You can find lots of our interesting posts and pages about the supervolcano here: Search Results for “supervolcano.”

Recently we happened upon this 2015 Q&A on Quora.com that busts several myths at once, in a friendly and concise way.

Q. Does it look like Yellowstone is going to erupt soon?

A. There are no signs that we know of that point to an eruption any time soon. However, since we have never seen a volcano like Yellowstone erupt, we can’t be sure what the warning signs of an eruption would be. Some sensationalist sources take every little twitch from the volcano, and even events unrelated to geologic activity, as signs of an impending eruption. Don’t take them seriously.

In better news, at least one study has suggested that the magma chamber beneath Yellowstone is partially solidified to the point that it currently cannot erupt unless it gets a fresh batch of hot magma from the mantle.

One little misconception that should be covered here: Yellowstone is not “overdue” for an eruption. The little factoid that Yellowstone erupts regularly every 600,000 years is untrue. So-called super eruptions occurred 2.1 million, 1.3 million, and 640,000 years ago, which gives intervals between eruptions of 800,000 and 660,000 years, though three eruptions are not enough to establish a reliable recurrence interval.

Credit: This answer on Quora was written by Nicholas Schiff, B.S. Geology, Mercyhurst University, Erie, PA.

In the guidebook: There’s much more in Yellowstone Treasures about the Yellowstone hot spot and supervolcano, especially in the Geological History chapter, pages 303 to 318.

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Updated for 2018, part 3

Categories: Geysers, Science
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Steamboat Geyser 4 June 2018

This photo of a major eruption of Steamboat Geyser gives a sense of its power but not its full height!

Every time we update the Yellowstone Treasures guidebook, such as for the second printing of the fifth edition in spring 2018, there are numerous changes to the hot springs and geysers that must be reviewed and considered. Not only that, “the number of hot springs in the park has been estimated to be around 10,000. Geysers known to have erupted or erupting now number more than 1,200” (Yellowstone Treasures, page 61).

Here are a few of the geyser changes since the cutoff date for the first printing, February 2017. During 2017 Atomizer Geyser (p. 96) noticeably slowed its interval down from twice a day to an average of 20 hours. Page 93 of the first printing says Giant Geyser last erupted on September 28, 2015 (and that was after a five-and-a-half year hiatus, so it was pretty important). But nature has been busy proving the guidebook wrong. Giant erupted on July 7, October 9, and November 3, 2017, so we included the November date as the last eruption. Now the most recent eruption was actually July 24, 2018, and that was the third time in the month of July.

We are fortunate to have a website called GeyserTimes.org, where geyser gazers can log their observations or the notes from a ranger or scientist at the US Geological Survey (USGS) Yellowstone Volcano Observatory. Readings from seismometers, thermometers, and water discharge monitors are used to record eruptions even when nobody is there to witness them. That is how we know that Steamboat Geyser started erupting again on March 15, 2018, too late to get into the second printing. On page 233, it unfortunately still says “After eruptions in 2003 and 2005, Steamboat erupted once each in 2013 and 2014.” Yet as of today there have been 11 more since March 15, with the latest occurring on July 20, 2018! The USGS is keeping a running count of Steamboat’s water eruptions at the Yellowstone Volcano Observatory page.

You may have a chance to see the Giant or Steamboat Geysers on your trip to Yellowstone. Stay informed with Yellowstone Treasures, both the book and this website.

—Beth Chapple, editor and publisher

Photo credit: James St. John, June 4, 2018. Reproduced courtesy of a partial Creative Commons license. More photos and more about the history of Steamboat Geyser is available at on the geologist’s Flickr page for this photo.

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Updated for 2018, part 1

Categories: Science
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Abiathar Peak


After a review by our consulting geologist, Jo-Ann Sherwin, we changed the sidebar on page 203, “Why do the mountains look striped?” The layers you can see on some mountainsides are not lava flows per se but deposits of material called tephra from volcanic eruptions. And the eruptions happened closer to 45 million years ago rather than the 50 mya it says in the first printing of Yellowstone Treasures‘s fifth edition and used to say in the nugget on this website.

You can read the nugget “How did these mountains get striped?” to see the new explanation. Stay informed with Yellowstone Treasures, both the book and the website.

Photo by Niklas Dellby, 2013

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Broad and beautiful Hayden Valley is where today’s visitors are most likely to see herds of bison close to—or on—the road. The valley is named for Dr. Ferdinand V. Hayden, born on September 7, 1829. He played a large role in the creation of Yellowstone National Park.

Trained as a medical doctor at Albany (NY) Medical School, Hayden served as a surgeon in the Union Army until 1865. However, he became interested in geology through collecting and studying fossils in the Dakota Territory and in 1867 began his government-supported geological surveys of the west.

During the summers of 1871, 1872, and 1878, the Hayden Survey studied the Yellowstone area systematically. The men observed and reported on many geological and other phenomena in voluminous reports. The report of Hayden’s first exploration was essential in convincing Congress to establish YNP in 1872.

Hayden’s love of geysers and hot springs reportedly could move him to tears. As an early guidebook writer observed: “He cannot compose himself in the presence of a geyser in eruption; but, losing recollection of the material world for the time, rubs his hands, shouts, and dances around the object of his admiration in a paroxysm of gleeful excitement.”

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Giving thanks nine ways

Categories: News
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male grouse display Yellowstone

Male dusky grouse displaying in Yellowstone National Park
(Click for larger image)

While Yellowstone has no wild turkey, there are several kinds of grouse and other similar birds in the back country. You might like this photo on Flickr by nature photographer Diana, of a female spruce grouse she saw at Dunraven Pass in the park.

In the spirit of Thanksgiving, and taking a cue from Janet’s Acknowledgments and Best Sights of Yellowstone pages in Yellowstone Treasures, Updated Fourth Edition, here are some of the people and places we are thankful for:

  1. Artist Point, an incomparable view of the Lower Falls and the Grand Canyon of the Yellowstone River
  2. our geology advisers, Bruno Giletti and Jo-Ann Sherwin, along with our other team members
  3. the Geyser Observation and Study Association and other supporting organizations
  4. Great Fountain Geyser, whose tall and exciting eruptions are safe to witness at close range
  5. Inspiration Point, with its outstanding view of Canyon colors
  6. Old Faithful Inn, the immense hundred-year-old log building that rivals its namesake geyser in beauty and interest
  7. the park rangers who protect Yellowstone and educate visitors
  8. the Yellowstone Heritage and Research Center
  9. you, our readers, who have kept us going since 2002!

Photo credits: The dusky grouse is an NPS photo in the public domain.

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Wonderfully clear and sensible statement about the Yellowstone volcano

Categories: News, On the Web, Science
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Thanks to the USGS and probably attributable to Jacob Lowenstern, this month we have a new statement from some of the world’s best authorities on the so-called Yellowstone supervolcano. They call it Five Things Most People Get Wrong About the Yellowstone Volcano, going at the problem of media sensationalism from the back side.

Lowenstern is Scientist-in-Charge of the Yellowstone Volcano Observatory and studies magma and volcanic phenomena in Yellowstone and all over the world for the United States Geological Survey, Menlo Park, CA.

The misconceptions this article lists are:

  • When Yellowstone erupts it will be Armageddon
  • The Yellowstone magma chamber is growing
  • Yellowstone is overdue for a supereruption
  • Yellowstone is rapidly rising
  • Earthquake data indicates moving magma.

All this is well worth absorbing and passing on to any worrywarts you know! And if you want to read more of the “true facts” (what are false facts?) about supervolcanoes, the Volcano Observatory has recently updated another great page by the world’s best authorities on the subject.

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Knowing that lots of people would like to learn how geysers work, I’ll take a stab at explaining the requirements and the mechanism as simply as possible.

What is required to create a geyser and what’s happening when it erupts? All geysers have four requirements: water, heat, the right kind of rock, and a system of conduits and reservoirs (plumbing) that includes one or more constrictions to keep water and steam from flowing freely to the surface. The water pooled above such constrictions acts like a lid to maintain pressure on water below. Such constrictions differentiate geysers from the much more common hot springs. Although no one has yet been able to see exactly what this plumbing looks like, it must be something like this diagramGeyser Mechanism Figure drawn by my husband Bruno Giletti for Yellowstone Treasures. The countless different shapes the underground plumbing may take must account for the great variety in the patterns and timing of Yellowstone’s geyser eruptions—what I call their personalities.

Whether the water comes from the vent in the distinctive cone of Beehive Geyser2004_BeehiveG. or from the beautiful geyserite-ringed pool of Great Fountain Geyser, 2008_GreatFtnG the mechanism is the same.

Deep below the geyser’s vent or pool seen at the surface is a kind of rock that is rich in silica. In Yellowstone this rock, called rhyolite, was deposited in huge amounts when the caldera erupted. Silica is the primary element in the hydrous silicon dioxide (technical name for geyserite) that is deposited both along the conduits of the geyser’s water passages and all around its surface vent.

Also deep below a geyser are (1) a source of heat—in Yellowstone it is the still extremely hot volcanic rocks more than two miles below the surface—and (2) the water that has seeped into the earth from snowmelt and rain (meteoric water), and voila!—the geyser erupts.

As water gradually fills the reservoirs and is heated from below, it becomes superheated and forms steam bubbles, and the water pressure increases. Eventually, the steam pushes some water out of the vent, and steam—which requires something like a thousand times more space than water—is also released. When the pressure is thus sufficiently reduced, the steam in the conduit can blow the water column out of the vent. In many geysers, when the water supply is exhausted, the remaining steam continues for the steam phase of the eruption.

I have gleaned some ideas for this post from the sidebar my husband Bruno Giletti, a geochemist, wrote in Yellowstone Treasures (pages 88 and 89) and from T. Scott Bryan, a former ranger and also a geologist and author of books about geysers, including his Geysers: What They Are and How They Work. But as early as the mid 19th century, German scientist Eberhard von Bunsen and others already had it pretty well figured out. You can find out more about the study of the geyser mechanisms here in my September 2013 post.

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One of the greatest pleasures of researching and writing is encountering ideas that are new and interesting to me. The concept of the Anthropocene is one such idea that I have looked into in some detail and want to share with my blog readers. My thoughts on the subject will come to you in a new series of posts.

The concept was new to me when I first heard the word Anthropocene at the fall 2012 annual San Francisco sessions of the American Geophysical Union (AGU). I have since discovered that although the word was recently popularized, fundamental justifications for its existence have been in the minds and writings of physical scientists for some time before that. This discussion has been taking place mostly among scientists and conservationists, yet is important to us all.

First let’s consider the word itself. It seems that British scientists have generated most of the interest in whether we humans have changed the earth enough to warrant the naming of a whole new epoch. People used other terms, mostly including the Latin prefix “anthropo-“ for human, here and there in the late 20th century, but they did not catch on. The suffix “-cene” means recent, as in Holocene, which until now has been the universally accepted term for the most recent geological epoch. How to pronounce Anthropocene? In lectures I listened to, most American speakers stressed the first syllable and most Europeans stressed the second.

Ever since Nobel Prize–winning chemist Paul Crutzen of the Max Planck Institute in Mainz, Germany, and Eugene F. Stoermer of University of Michigan—Ann Arbor proposed the term [1] in 2000, the stratigraphic branch of geology has been debating whether or not to formally accept Anthropocene into their lexicon and when it can best be said to have begun. (Stratigraphy is the branch of geology that deals with the origin, composition, distribution, and succession of strata.) A Working Group on the Anthropocene has been set up to decide questions regarding the new word by 2016, a year chosen to coincide with the International Geological Congress.

My next post on this subject will discuss the issues involved in the decision.

References

[1] Crutzen, P. J. and Stoermer, E. F. “The ‘Anthropocene’,” in the IGBP Newsletter, pp. 17-18, May 2000. Available at: http://www.igbp.net/download/18.316f18321323470177580001401/NL41.pdf

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The magma system or reservoir under Yellowstone is 2.5 times larger than previously known

Recent articles including “supervolcano” in the headline in the blogosphere and in media such as the New York Post shout “We’re probably doomed” and tell us of “a volcano that could wipe out U.S.” That gets people’s attention! The whirl of media activity is all due to research presented at last week’s American Geophysical Union (AGU) annual meeting in San Francisco.

An interesting session and a poster presented by Drs. Robert Smith and Jamie Farrell have stirred up a lot of emotional response, as has a November earthquake swarm in the area. The more these things are discussed in the media, the less rational readers seem to become. Media loves sensation. Perhaps the scientists whose work inspired the sensationalism will soon issue something to calm people down. Meanwhile, I’ll do what I can with this post.

I attended Smith’s 15-minute session at AGU and read Farrell’s poster last week. I am not a scientist, but I know enough about Yellowstone and current research to say this: The size of the magma reservoir below Yellowstone tells us nothing about when it will explode. Just as a reminder, magma is liquid or molten rock, including any dissolved gases or crystals, found deep within Earth.

More and more researchers are using various methods and instruments (seismometers, strainmeters, geochemical analyses, geodesy, instruments measuring electrical conductivity, and so on) to study what is under Yellowstone and its surroundings. Let’s wish them well and not panic about a catastrophe that is very unlikely to happen within the lifetime of anyone who can read this.

What about those earthquakes? One useful conclusion reached by this recent research is: “A large earthquake at Yellowstone is much more likely than a volcano eruption,” according to Farrell.

ON THE WEB: Here is some reliable and interesting information:
1. University of Utah’s Seismology and Active Tectonics Research Group’s faculty member Bob Smith stated on December 5th that U. of Utah’s seismographs will “continue to monitor Yellowstone earthquakes and will provide additional information if the earthquake swarm activity increases.”

2. U.S. Geological Survey’s Yellowstone Volcano Observatory. Swarms of (usually small) earthquakes have been reported frequently over the years; they are detected by the USGS seismograph array in Yellowstone.

3. Phys.org’s article called “Study: Yellowstone magma much bigger than thought (Update).” A relevant quote serves to sum up my comments here: “For years, observers tracking earthquake swarms under Yellowstone have warned the caldera is overdue to erupt. Farrell dismissed that notion, saying there isn’t enough data to estimate the timing of the next eruption. ‘We do believe there will be another eruption, we just don’t know when,’ he said.”

ON THIS WEBSITE: For more about the quest to understand what’s under Yellowstone, be sure to read the nuggets called “The Yellowstone Supervolcano,” “The Yellowstone Hot Spot: History of the Science“, and “The Yellowstone Hot Spot: Modern Science“.

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Dynamic Earth: Yellowstone geology doesn’t stay the same

Categories: Science, Thermal features
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Yellowstone Treasures‘s geology writing strives to keep up—

If you were to contemplate nature’s many facets and how quickly things change over the seasons and the years, you might think that you can at least count on the rocks and the mountains to stay the same. Wrong! Geoscientists will tell you that even mountains have their own dynamics. But their rate of change is much slower than humans can easily grasp in their relatively short lifetimes. Nature shapes the land we live on over centuries and millennia, but the rate at which geoscientists learn about it using new methods, ideas, and equipment is constantly accelerating.

Wanting to keep track of all this activity as it pertains to Yellowstone Park for the updated fourth edition of my guidebook, I was delighted when my old friend Dr. Jo-Ann Sherwin offered to bring us up to date about Yellowstone’s geology. I’ve known Jo-Ann ever since she was an outstanding student, whose advisor during her Brown University PhD research was my first husband Bill Chapple. She was the first woman to earn a PhD in their geology department and has gone on to a long career in research and teaching. She also lives in Idaho Falls, convenient to the west side of Yellowstone.

Jo-Ann reviewed the entire book and made numerous suggestions. She also rewrote large portions of our geological history essay, “The Stories in Yellowstone’s Rocks.” Our goal is to make our explanations accurate but concise and as clear as possible without any technical writing. Here’s a short sample from our essay that draws upon recent research into the source and age of the water for the park’s thousands of geysers and hot springs (hydrothermal features):

What makes the different hydrothermal features do what they do? Basically, the great volume of groundwater is heated by very hot rocks quite near the surface at Yellowstone.
There is a very large amount of old groundwater, at least 60 but perhaps greater than 10,000 years old, just above the magma below Yellowstone. The source of this water may have been the glaciers that covered the area or rain and snow in the surrounding mountains, 12 to 45 miles (20 to 70 km) distant. Present-day rain and snowmelt seep down and mix with this old water, become warmed to the boiling point, boil into steam, expand greatly, and find a way to escape upward. Most of the features occur where faults are common, making it easy for the heated groundwater and steam to return to the surface.

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