Monday, August 7, 2017

Learning to map while also respecting the land

-Alison


The scale of geologic history is not just spread over a larger time span than many of us are used to thinking about, but also a larger physical scale. To help train future geologists to be comfortable with these large scales, and three dimensional challenges of our planet's history, we take students out into the field and make them map, the old fashioned way, by hand. I went with the UMKC field camp this June to learn about the places and projects that we use to train our geology majors as I will likely take over leading the camp in the future.

UMKC field camp students putting boots on rocks and pencils to paper to gain experience making geologic maps in South Dakota.

For many people the idea of making a map seems outdated. People hear words like map and geography and assume that it is all done, and they only have to worry about changing country boundaries. Maps, however, are a means of conveying information in a spatial way, that doesn't just include geopolitical boundaries and bodies of water. For a geologist mapping is still a critical step in unraveling any geologic problem. It is important to understand the types and distribution of different rock types, how they change with distance and contact each other. Maps are one of the first steps to figuring out how to get more of a resource such as oil, metals, or coal. We can map what is exposed on the surface, and what is underground. We can map what is on Earth and other planets. While there are many amazing maps already in existence around the world, we frequently find new questions that are at a different scale of interest, or need data that the previous maps didn't include. 

Geology is wonderfully messy and one of the best ways to start thinking about how the Earth changes over time is to go visit some messy rocks, like these tilted strata near Buffalo Wyoming.

This simplified geologic map of the state of Missouri shows the major rock types. The county lines are drawn to help the reader figure out where they are, but the important information is all in the colors. The red and blue spots in the south east are where all the cool volcanic rocks are. From Wikimedia Commons with data from the Missouri Spatial Data Information Service.


We can also use maps to identify and measure change in an area or to show what change has happened in the past. If you want to understand a hazard in a given area you must know when and how often an event happened. The state of California has what is called a landslide inventory which was produced using data from decades of mapping. Geologists can also reconstruct the rocks as they were before the event (landslide, earthquake etc.) and then figure out what changed, by how much and when.

Earthquake Lake Montana was formed in 1959 when an earthquake produced a landslide that dammed the Madison River. The drowned trees still stand as a testament to the changing landscape. We visited to help the students identify the evidence for the event in the geology and vegetation. We also got to see bald eagles and beavers making their homes here.
Maps are also a means of communicating information, not just recording information. For volcanoes we frequently map the extent of deposits from past eruptions. For instance, how far did ash travel away from the vent. We can also make a map that shows thickness of that ash, or where the largest blocks from that same eruption landed. One of the most distinctive maps for volcanoes are hazard maps, which exist to show what areas are likely to be affected by different hazards during a future eruption. This is also done for floods, landslides and tsunamis.

This hazard map of Mt. Hood from the USGS was made to communicate where the main hazards from a future eruption are likely to affect the area surrounding Mt. Hood. Note how the lahars follow valleys and go well beyond the slopes of the mountain. The amount and type of information on the map will vary depending on the purpose of the map.


Students at field camp learn to find themselves on the map using topography (not as easy as it sounds when you first start), how to recognize different rock layers (even when they get messed up by faults, erosion, and volcanic events), and how to communicate what they observed. All these skills are introduced during course work, but it is really out in the field, with real messy rocks, that students finally get a chance to test and hone their skills.
Several of my undergraduate research students at field camp looking epic with Bear Butte in the background, June 2017. This shot was only 1/3 posed.
There is also another less obvious lesson that students get in field camp, they learn about the land in more human terms. Field geologists get to travel to many awesome places. One of the aspects of that field work is getting permission to access land, to climb fences, collect samples and take photographs. Geologist in the USA work on federal land, state land, private land, and American Indian Reservations. Many times this land changes designation over time. Respecting modern and historic designations is important for the preservation of the land and respect of the residents and other users of that land. Land is important to many people for different reasons and it is important to not forget that in light of our own immediate motives, even in the name of education.

National parks, like the Badlands featured here, are an important resource to experience the diverse geology of the US and other countries. It is important to pay attention to the expectations for visitors when enjoying these spaces so that they are preserved for future visitors.

This means leaving your hammer behind if necessary, sticking to trails in designated areas, and carrying permits with you all depending on the regulations of the location where you are working. It is also important to acknowledge the ancestral lands that geologist get to work on. They may now have federal or private designations, but these beautiful places that I revere for their geologic wonders have significance beyond as a spot for training future geologists.

Our field camp spends a significant amount of time working the traditional territories of the Lakota Nation. The Lakota are one of seven related Sioux Tribes that have ancestral territories across the Great Plains of the United States and Canada. We visited several important sites around the Black Hills including Wind Cave, Devil's Tower, and Bear Butte.
Devil's Tower South Dakota. Lakota, Arapahoe, Chyenne, Crow, Shoshone, and Kiowa people still visit and leave tobacco pouches and prayer offerings on the mountain honoring the spiritual significance of this site.
There are many peoples who value natural landmarks and it is important to remember that they are significant beyond our own appreciation. This plaque in the National Monument Visitor's center shows many of the names for Devil's Tower.

Devil's Tower significance to me is in its excellent columnar cooling cracks (when hot rock cools it contracts and if cooled slowly will form regular cracks) and it is a place I've wanted to see since I was a child (and first tried to make it out of mashed potatoes ala Richard Dreyfus). There are many Native oral histories explaining these marks, but they typically involve a bear (see names) scratching the side of the rock to produce its distinctive shape. In some narratives the bear wandered east to lie down and form Bear Butte near Rapid City. These landmarks are part of a larger landscape and a larger history than we see day to day. It is the job of geologists to look at how the landscape connects geologically, but I am glad we get the opportunity to see it from many other important perspectives as well.
Bear Butte in Western South Dakota. The Butte viewed from the south doesn't resemble a bear so much, but since that is where we mapped I never got a photo from the west to illustrate it.
Wind cave is also important to the Lakota and Cheyenne as it is a key location in the creation story of the people of the plains. It is home to most of the world's box work, and was the first cave ever to be preserved as a national park. That is a lot of things for something as fragile as a cave to be.
Box work is unlike stalactites and stalagmites that most people associate with caves because it forms in the dissolution of the limestone, rather than growing with time. This means these features, once damaged, are gone. The bulk of the world's discovered box work occurs in this one cave system! The beauty and fragility makes preserving these features a challenge.
I'm likely to take over field camp next year, and the prospect is daunting, but exciting (oh the logistics...). Field camp is an important opportunity for students to really become immersed in geology and grow as scientists and as people. It can be challenging, uncomfortable (heat, learning to avoid snakes, high elevations), and fun. I still remember my own field camp and the confident realization that I wanted to do this, learn about our planet, for the rest of my life. I look forward to continuing to work with students in amazing places like these and learning more about the geology, and the human history of these landscapes each year.

Want to see some awesome maps?
The United States Geological Survey (USGS) has a lot of maps available online, including Geologic Maps. Same with the British Geological Survey (BGS). Make sure to check out your local geological survey at national and state / province level for what is available on the area you live in.
Want to recognize the ancestral history of the land you are living / working on? 
While I don't have just one weblink to provide for this, a bit of internet research usually reveals what you are looking for. If you don't know where to start, look by region or for nearby major landmarks. There are usually multiple resources to track down the ancestral and historical claims on your field area.


1 comment:

  1. Great post about the importance of mapping to geology. Well done.

    ReplyDelete