The Ant Hill Advantage



-Alison

So for the last two weeks both Janine and I have been off on separate field adventures. This is not uncommon for geologists in the summer. School ends and we dash off for locations with rocks we cannot get at home. I plan on doing a longer post on the cool things I observed about the insides of old eroded volcanoes soon, but not just yet as the travels are not done!


Ant hill made up of volcanic minerals from the Hopi Buttes Volcanic Field, Navajo Nation, AZ, USA.
I did want to share a fun factoid about how ants help geologists when searching for specific rock types by using some examples from my recent field work. Whether or not you had an ant farm as a kid, its pretty easy to imagine the process involved in building an ant colony. The ants excavate tunnels underground and move the material from their tunnels to the surface. This material, moved grain by grain, adds up and can form a hill. As the ant colony gets larger, they bring up material from deeper underground. This helps geologists because it brings minerals to the surface that may be just out of sight. Because we live on a planet with weather (yay atmosphere!) and liquid water, the surface is constantly changing. The ants kindly bring up minerals and rocks that were buried by soil, wind blown dust, or plants and let geologists know where to look.

For example, in the Hopi Buttes Volcanic Field in the Navajo Nation, AZ, USA the deposits contain a lot of pyroxene. The old volcano insides (dikes, diatremes, etc.) stick up as obvious buttes, but the edges of these rocks are worn down and this makes it hard to figure out just how big the volcanic plumbing system was.
Buttes of black volcanic rock surrounded by red sand and siltstones of the Chinle Formation in the Hopi Buttes Volcanic Field.

To figure out where the contact between volcanic deposits and the old host rock is (in this case, sandstones and siltstones) we could use the ant hills to get a better idea of what rock was below us even in flat areas. If the hills were shiny and black, they were digging in the volcanic rocks! If they were red or pink, those were host rocks. We still dig holes to check, but they give us a head start.
Concentration of pyroxene crystals and small pieces of lava in an ant hill.

Another example was from the Dotsero Maar in Colorado, USA. We were tracking the ash deposits from the eruption (possibly as young as 5,000 years ago, making it the youngest eruption in Colorado). Ash quickly turns to soil and gets covered in plants and other debris. To check the location and thickness of the ash we needed to dig lots of holes. Kindly, ants brought up lapilli (pebble sized pieces of scoria) in areas where there were ash deposits and helped us to know where to dig. As digging in 100 F heat is hard work, we appreciated any advantage we could get.


Digging for ash deposits. We could use the ant hills full of lapilli to know we were in a good spot.

There is actually a long history of geologists using ant hills to find minerals when prospecting. And even one case where other prospectors were known to plant minerals to trick their competitors into following false trails! If you want to read a neat book about prospecting, with proper credit to ants, I suggest Barren Lands which is a good way to learn about kimberlites and diamond mining.

Next week I'm off to Italy, so that will mean even more photos and stories to share later this summer.

Popular Posts

It's all for you, girl! A message to girls everywhere from the women in volcanology

Image
- Dr. Janine Krippner It saddened me to see a new study published a couple of weeks ago that tells us girls from the age of six are prone to thinking that they are not as smart as boys. What is even more sad is that this wasn't really a surprise. You only have to look at how the media portrays women to get an idea why. When I was a little girl my Mum told me that I could be anything I want to be. I believed her and I am passing this message on to you. I know some of you have it much harder than others, harder than I could have imagined as a little girl. Don't give up and follow your dreams. I have asked women volcanologists from around the world to tell you what they do, why they love their work, how their work makes a difference in the world, and to give advice for girls everywhere. Of course this advice is not limited to girls, boys are also subject to messages that they are not good enough, and this can be much worse depending on race, religion, sexual orientati
Read more

Agung Volcano Unrest Information

Image
- Dr. Janine Krippner I am NOT giving my own interpretations of the data and what the data means. I am NOT, and CANNOT tell people what this volcano might or might not do. Please always refer to all official source links below. The utmost respect must be given to the local authorities monitoring Agung. I am not in Bali, nor am I an authority on Agung Volcano. I have not worked on Agung volcano, or any Indonesian volcano for that matter. Always look to the official sources for information, or to verify any information. Official sources of information: Twitter: Magma Indonesia ,  Sutopo Purwo Nugroho ,  BNPB Indonesia ,  PVMBG-CVGHM Websites: Magma Indonesia Website , BNPB website , ESDM Website Facebook: BNPB I have been getting a lot of questions from travelers who are in, or planning on being in, Bali. Many travelers don't know where to get official information, cannot read it as it is in Indonesian, and do not, understandably, understand what it means. So, right now I
Read more

Communicating Volcanoes: Resources for Media

Image
- Dr. Janine Krippner Watching the Agung eruption unfold showed me firsthand some of the points of confusion when it comes to talking about volcanoes and eruptions. You can see the types of information and resources I gave during that time here . Below are resources that can help understand terminology and processes, and find authoritative sources of information. There are definitely more trustworthy websites than others and I provide them below. This is not a complete list and I will keep adding to it. Communication is not my field of research (explosive volcanism is), this is purely based on my experience doing outreach on social media and working with media. If you have anything else that you would like to see added here, please let me know. Pavlof volcano erupting in Alaska in 2016. Courtesy of the Alaska Volcano Observatory. Firstly, what is a volcano? A volcano is an opening in the Earth where either solid, liquid, or gaseous materials come out of the Earth's surfa
Read more

Back in time to Mount St. Helens: News coverage of the 1980 eruption

Image
- Dr. Janine Krippner Today marks another anniversary of the deadly eruption of Mount St. Helens volcano in Washington, USA. This eruption was one of those events where most remember where they were around the world when they heard the news. It changed the lives of those around the volcano - those who lost friends or family, their homes, their view of the local landscape, and their belief that 'it won't happen to me'. Fifty-seven people were lost, including volcanologist David Johnston ( his biography is out now here ). People around the world know this volcano after this day. Mount St. Helens on May 18, 1980. Courtesy of USGS. Thirty-nine years ago the world watched as the eruption took place, so what did they see? What it was like for those who experienced the eruption firsthand? What did the rest of the country see through the experiences of reporters and those who were there? When the next continental-US volcano erupts some of us will be there. Some of us wil
Read more

Volcanic ash is not fluffy & volcanoes don't smoke! Setting the story straight & how to protect yourself.

Image
- Dr. Janine Krippner Mount St. Helens, May 18, 1980 . Top information resources for volcanic ash: USGS Volcanic Ash Impacts and Mitigation The International Volcanic Health Hazard Network  GNS Be Prepared: Volcanic Ashfall Global Volcanic Hazards and Risk  List of Volcano Observatories Items to stock before ashfall As you read this, there are likely around 20 volcanoes actively erupting right now. There are over 40 ongoing eruptions around the world. There are 1,431 volcanoes that we consider to be potentially active, or that erupted recently enough to be able to erupt any time soon ( list here ), and there are hundreds of millions of people living around those volcanoes . On top of that, there are many people who travel to or near volcanoes, and even more who fly around the world in planes that can be impacted by volcanic ash . Freight planes and ships can be halted and economies are impacted. As you see in this first video that was taken at Mount St. Helens
Read more