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Tuesday, December 12, 2017

Temperature Inversion - Air Pollution Montana-Style

This photo of a temperature inversion was taken from Bompart Ridge on the southern edge of Helena, Montana on Sunday, December 10. Cold air was sitting in the valley below. The temperature on the valley floor was ~15 F, and it was ~20 F on this ridge. The reason you can see the cold air is that it fills with fog and pollution.

Its a valley thing.
During winter months, the mountain valleys of western Montana are prone to inversions – called this because they really are "upside-down situations". NORMALLY the atmosphere gets colder as you get farther away from Earth's surface because the air is warmed from the bottom up by heat given off by the Earth. However during inversions, air at the surface is much colder than the air above. Local hikers know this means that it can be 5-10 degrees warmer on top of the mountain than it is down at the trailhead.

Recipe for a temperature inversion - Clear, Calm, Cold
Mountain valleys serve as “sinks” where cold, dense air may sit for several days. They develop during clear, calm, cold nights – especially in December and January. Clouds act like a blanket, keeping much of the heat given off by the Earth close to the surface. So, on clear nights this heat escapes quickly out to space, and air at the surface becomes cold (and heavy). The low angle of the Sun in December and January prevents this valley air from heating up during the days. Snow cover, which reflects sunlight, and the shortness of winter days also help prevent it from warming. If the inversion persists for several days, air quality worsens as the stagnant, cold air fills with pollutants such as smoke from wood-burning stoves or emissions from automobiles.

For more about this (blog with photo tour) CLICK HERE.

Monday, December 4, 2017

Ancient Sea-Floor Sediments Store Huge Amounts of Carbon.

Click on the photo to see higher resolution.

Got carbonates?
Scapegoat Mountain (elevation 9,186) is located in the Scapegoat Wilderness of western Montana. Both the cliff and peak are made of layers of carbonate rock deposited during the Cambrian Period (540-485 million years ago) when Montana was beneath a shallow part of the ocean as shown on this map. The cliff consists primarily of two limestone formations; the Pagoda formation lies beneath the Steamboat formation - and the peak is made of Devil's Glen dolomite. Limestone is mostly calcium carbonate (calcite, CaCO3), whereas dolomite is calcium magnesium carbonate. Dolomite can form as magnesium-rich groundwater moves through limestone, giving magnesium ions a chance to replace calcium ions.

Not that kind of reservoir.
Dolomites and limestones store huge amounts of carbon, hence they are an important reservoir of carbon and part of Earth's carbon cycle. It is estimated that Earth's carbonate rocks store over 60,000,000 gigatons of carbon, compared to the estimated 840 gigatons in the atmosphere (Source: burnanenergyjournal.com). Atmospheric carbon is mostly in the form of CO2, and experts believe that CO2 levels during the Cambrian Period were much higher than today. Movement of this carbon from the atmosphere to the rocks shown in the photo began with rain. Carbon dioxide combined with cloud droplets to form a weak carbonic acid that rained to the surface. This acidic rain "ate away" rock material (chemical weathering), releasing calcium, magnesium, and other ions that rivers carried to the ocean. In the ocean, the calcium ions combined with bicarbonate ions to form calcium carbonate, which precipitated to the sea-floor. These processes were certainly in high gear during the Cambrian Period as evidenced by the thickness of the carbonate layers shown in the photo. In fact the carbon in the cliffs of Scapegoat Mountain has been stuck there for 500 million years. So, what natural process(es) could put some of these carbon atoms back into the atmosphere? Read this to find out.

A couple "plot twists" in the carbon saga.
In modern oceans, most of the carbonate material being deposited originates from corals and shell-building organisms, including plankton (foraminifera, etc.). As these organisms die, they build up on the seafloor. Eventually layers of shells and sediment will be cemented together and become rock, storing the carbon in stone (limestone and dolomite). Another way that carbon is stored is as fossil fuels. Under certain circumstances dead plant matter or algae builds up faster than it can decay, Then as these deposits of organic carbon are buried and compressed they become oil, coal, or natural gas instead of sedimentary rock. (Source: NASA - The Slow Carbon Cycle)

There's been a disturbance.
Scapegoat Mountain sits near the southern end of the Lewis Overthrust Belt, which includes the spectacular mountains that extend northward through Glacier Park, into Canada. The overthrusting happened as the Pacific Plate pushed into North America starting in the Middle Jurassic Period (174 to 163 mya) and ending in the Early Eocene Epoch (56-34 mya). The super-slow collision forced slabs of crust (mostly sedimentary rock) to fault, and then slip up and over younger layers to the east, resulting in the unique north-south trending ridges and valleys found along the Rocky Mountain Front.

The "Bob" is a great Montana place.
The Scapegoat Wilderness is part of the Bob Marshall Wilderness Complex south of Glacier Park - The fifth largest wilderness area in the lower 48 and home to some of the most primitive back-country in the USA. Affectionately known as "The Bob," the complex consists of three wilderness areas, including the original Bob Marshall, which was established in 1964, along with the Scapegoat and the Great Bear Wildernesses, which were added in the 1970s.

To learn more about Scapegoat Mountain and see many more photos, CLICK HERE.

Saturday, November 11, 2017

Carbon Cycle Video - Short, sweet, and to the point.

I came across this 3-minute video while looking for a good way to introduce my ninth-graders to the carbon cycle. It's a good starting point. After you watch the video, check this out as well.

Monday, August 7, 2017

Chief Mountain - A classic "klippe" in Glacier Park

As an Earth Science teacher, I felt like a kid in a candy store during this hike. Chief Mountain the classic example of a "klippe" (associated with the overthrust that formed Glacier Park), plus we had great views of a landslide that happened in 1992, Slide Lake, and a weird vegetation pattern (shown in photo above; not sure how it formed). CLICK HERE to access the blog, which includes a photo tour of all that we saw.

Thursday, July 20, 2017

Logan Pass on Continental Divide - Glacier Park, Montana

Logan Pass (elevation 6,646 feet) on the Continental Divide is the highest point on the Going-to-the-Sun Road in Glacier National Park. Although there are higher areas in the south-central part of the state, Logan Pass gets more precipitation than any place in Montana. Mountains along the divide force moist air from the Pacific upward, causing cooling by expansion. As the air reaches its dew point, vapor changes to snow (or rain). Also, Arctic air often moves into Montana along the east side of the divide, contributing to the lifting and cooling of Pacific air from the west. An area just east of Logan Pass, called “The Big Drift”, often records over 80 feet of snow, much of it pushed there by strong westerly winds that blow in the winter. A record gust of 139 mph was recorded in April of 2014.

The Going to the Sun Road, which can be seen in the photo, is one of the most scenic drives in the USA, and also one of the most difficult to snowplow. Crews usually begin plowing in early April, and the road is usually open from early June to mid-October, with the latest opening date being July 13, 2011 due to tremendous amounts of snow that fell that winter. The road, which was completed in 1932 and opened in 1933, connects the east entrance of the park (St. Mary) with the west entrance (near Lake McDonald). Although there aren’t many glaciers left in the park, the road provides visitors with excellent views of features carved by glaciers, including, hanging valleys, horns, glacial troughs, arĂȘtes, and cirques. For those who want a closer look, there are several hiking trailheads along the highway, including the spectacular "Highline Trail" that starts at Logan Pass. The trail passes above the highway and below a portion of the Continental Divide known as “The Garden Wall.” The Highline Trail can be seen on the left side of the photo - between the highway and the patches of snow.

More information

1. Peak Bagging Near Logan Pass (many more photos)

2. Hiking the Highline - best trail in the park

3. Montana Precipitation Map

4. Wikipedia: Going to the Sun Road

Tuesday, June 6, 2017

GREAT eclipse site from NASA - Must see!

Thanks to Rick Dees for sending this one my way. The total eclipse of the Sun will happen on Monday, August 21 this summer. Make plans now!

CLICK HERE to find out what it will look like from various locations. You can zoom, tilt the globe, or select a new location. THIS IS GREAT! It shows what it will look like from your location, including the timing. *See credits below.

Map courtesy of www.greatamericaneclipse.com/nation/.

*Credits
Producer: Kevin Hussey

Ranger Task Manager: Marc Pomerantz

Software Engineering Team Lead: Andrew Boettcher

JPL Ranger Software Engineering team: Andrew Boettcher, Michael Hans, Anton Kulikov, Mi Nguyen, Marc Pomerantz, Michael Sandoval, Davit Stepanyan, Brian Wright

Additional JPL support: Jason Craig, Matthew Garcia, Kevin Hussey, Daniel Sedlacko

UI Design and Development: Moore Boeck

Copyright 2017, by the California Institute of Technology. ALL RIGHTS RESERVED. United States Government Sponsorship acknowledged. Any commercial use must be negotiated with the Office of Technology Transfer at the California Institute of Technology.

Friday, June 2, 2017

Montana Lake Carved by Outburst Floods During Ice Age

Lots of geology going on here. Two of my hiking buddies are standing on the remains of a laccolith looking at Lost Lake whose basin was carved by outburst floods during the last ice age. The mountains in the background (Highwoods) are the remains of an ancient volcano that was active 50 mya.

After visiting Lost Lake we hiked up onto Square Butte (another laccolith). Both features are made of rock formed as magma cooled beneath the surface tens of millions of years ago. However, the story of Lost Lake includes another chapter that involved an unusual set of circumstances that happened during the last ice age. To learn how outburst flooding of Glacial Lake Great Falls was involved, go to bigskywalker.com.

Friday, May 19, 2017

GREAT 13-minute segment about Mars from "60 Minutes"

In case you missed it, this is a GREAT segment that includes several important Earth Science concepts - Earth's magnetic field, plate tectonics, law of superposition, erosion, meteorites, etc. Consider showing it as you teach about the rock cycle. Here are some possible questions to guide a discussion after showing it.

1. Is there a "rock cycle" on Mars?
2. How is it different from the rock cycle on Earth? What processes are missing?
3. Is there molten rock on Mars?
4. Are there metamorphic rocks on Mars?
5. What drives the rock cycle on Earth?

Sunday, May 14, 2017

Convection - The straw that stirs the drink.

Whether you're talking atmosphere, oceans, or mantle, one of the most important processes in Earth systems is convection. Here is one of our favorite activities for our freshmen Earth Science students at Helena High. The lab, which has two parts, allows students to see convection as it happens. The part shown in the video below focuses on helping students understand the role convection plays in causing wind. The box of water represents air.

The lab comes in a kit we purchase from WARD'S Natural Science, which includes this 2-part activity plus another activity related to ocean currents. The kit is called "Exploring Convection." To make the blue ice cubes, add 3 drops of food coloring to each empty cube mold in an ice cube tray, add water, and freeze.

CLICK HERE to see a video of "Part I".

CLICK HERE to see a video of the other lab included in the kit (related to ocean currents).

Friday, April 21, 2017

How the USA Generates Electricity

Check out this interesting Washington Post site, which includes several informative graphics. Every student should have some sense of where electricity comes from? Once the site opens, be sure to scroll down and select the different types of energy to see how each state generates electricity - Just below where it says, "Click to rearrange."

Friday, March 31, 2017

Glacial Striations on Snake Butte


Click on the image to see a larger view.

This photo, taken on Snake Butte in north-central Montana, shows scratches that were made as the Laurentide Ice Sheet (continental glacier) flowed across here during the last ice age. Rocks that were stuck to the bottom of the ice caused the gouges - called "striations." Snake Butte is about 10 miles south of Harlem, MT on the Ft. Belknap Indian Reservation. The Little Rockies can be seen in the distance.

Striations help determine which direction the glacier flowed as it grew across the land, and also help locate "spreading centers" where the ice grew FROM, before merging to form the single continental glacier that covered Canada. Striations found in various parts of Canada reveal that there were three places in northern Canada where snowfall accumulations contributed to the ice sheet that eventually reached the USA (Of course there was no USA at that time!). These striations on Snake Butte prove the glacier flowed toward the southeast as it moved over the butte - probably because the Bears Paw Mountains (several miles southwest of here) forced the ice in that direction.

Below: The black dashed line indicates how far south the ice advanced into Montana when the ice age peaked about 18,000 years ago.

In addition to striations, the Laurentide Ice Sheet left other clues in the Snake Butte area.

1. Erratics – Metamorphic rocks from the Hudson Bay area can be found on Snake Butte (and throughout northern Montana). These rocks, which were embedded in the ice, were dropped here when the ice melted.

2. The Snake Butte Boulder Train – Large pieces of Snake Butte (igneous rock) have been scattered in a straight line extending to the southeast of Snake Butte. As the glacier flowed across the butte, pieces of the butte were carried away, and eventually dropped as the ice melted. Although they are few and far between, the line extends for almost 50 miles. The direction of the boulder train matches the direction indicated by the striations.

For much more about Snake Butte, CLICK HERE (includes a photo tour).

Sunday, March 26, 2017

Concretions Along the White Cliffs of the Missouri River

There are several places in and along the White Cliffs of the Missouri River in north-central Montana where you can see great examples of concretions. A concretion is a roughly spherical mass of sandstone embedded in less durable sandstone. Concretions form within layers of sand/sandstone that have already been deposited, usually before the rest of the sand has hardened into rock. Concretions form when a mineral precipitates and cements sediment around some sort of "nucleus", which is often organic - a leaf, tooth, piece of shell or fossil. Fossil collectors sometimes break open concretions in their search for fossil animal and plant specimens. The "concretionary cement" often makes the concretion harder and more resistant to weathering than the sandstone it is embedded in.

Below: Here are a couple more photos of concretions along the White Cliffs of the Missouri. This 47-mile stretch is one of the premier canoe/kayak trips in the USA. CLICK HERE for an account of the 3-day journey (lots of photos). Here is another link to more information about concretions, including a short video (does not open on many mobile devices).

Sunday, March 19, 2017

Strange Fossils in Glacier Park

These are fossils of stromatolites that can be seen along one of the most popular trails in Glacier Park. CLICK HERE to see more photos taken along the Highline Trail.

Glacier Park is made almost entirely of rocks from the Belt Formation (aka "The Belt Supergroup") - layer upon layer of sandstones, shales, and carbonates from the late Precambrian Era. At that time there were no organisms with bones or shells, so stromatolites like those shown in the photo, are the only fossils that can be found in Glacier Park.

Stromatolites are mound-like, multi-layered colonies of algae (blue-green algae; aka cyanobacteria), and their formation has much to do with the way they change the chemistry of the shallow water they live in. The photosynthetic cyanobacteria remove carbon dioxide from the surrounding water, causing calcium carbonate to precipitate onto their slimy, mat-like colonies. Calcium carbonate, along with grains of sediment (silt, etc.), stick to the bio-film layer that covers the colonies. As the cyanobacteria continue to grow up through the sediment, a new layer forms. This process occurs over and over again, creating layered mounds, columns, or sheets.

Fossils of different species of stromatolites can be found in different areas of the park. Stromatolites that lived in the Precambrian played a major role in increasing the amount of oxygen in the atmosphere of the primeval Earth ("The Great Oxygenation Event"). Living stromatolites can be found today at Shark Bay in western Australia.

Check out my Montana Hiking Blog - lots of geology!

Source: T.N. & E.L. Taylor. 1993. The Biology and Evolution of Fossil Plants. Prentice Hall, New Jersey.

Wednesday, February 22, 2017

Great explanation of "Rain Shadows"!

This video is fron a YouTube channel called "2 Minute Geology", which focuses primarily on the Northwest USA (especially Washington). It is produced by Tom Foster and Nick Zentner (Central Washington University).

Thursday, February 16, 2017

Laccoliths, Dikes, and Bears - Oh my!

I recently explored several plutonic formations associated with an ancient volcanic field in central Montana. The volcano(es), which was active during the late Cretaceous period, left its mark on the landscape in the form of several laccoliths, dikes, and sills. Centuries ago the sill shown in the photo below was used as a buffalo jump by Montana's first people. That is my shadow on the cliff. CLICK HERE to learn more about the trip and access the photo tour, which includes some nice shots of the bear that inspired me to climb a tree.

Saturday, January 28, 2017

Hiking into the Crater of Mt. St. Helens

This photo was taken during a hike that I did a few years ago into the crater of Mt. St. Helens. The landscape was rocky and gray with hardly any vegetation - but VERY interesting. Plus, we were treated to an "up close and personal look" at geology in action - glaciation, volcanism, and a canyon being carved by melt-water from Crater Glacier. As an Earth Science teacher, I felt like a kid in a candy store. For more about this trip (many downloadable photos), CLICK HERE.

The photo was taken below the crater on the north slope of the volcano. Loowit Creek originates from melting snow and ice in the crater. Much of the water comes from Crater Glacier, which has formed and grown around the lava domes over the past several decades. Loowit Creek has cut down through the volcano, exposing the alternating layers that give composite volcanoes their name. Also known as stratovolcanoes, volcanoes like St. Helens consist of alternating layers of explosively erupted pyroclastics (ash, cinders, etc.) and lava flows.

Thursday, January 19, 2017

Fascinating Geology of Ear Mountain in Montana

Photo courtesy of Sam Beebe, www.ecotrust.org

The front of what?
Ear Mountain stands along the boundary between the mountains and the prairie 70 miles northwest of Great Falls (map); an area Montanans refer to as “The Front”. The name probably originates from the view enjoyed by those approaching from the east - That of a long wall marking the abrupt end of the great plains and the beginning of (front of) the mountains. The area, which extends northward to Glacier Park and beyond is known for its scenic beauty, grizzly bears, Chinook winds, and fascinating geology.

Sea creatures in Montana?
Ear Mountain along with many of its neighboring ridges, peaks, and cliffs consist of the Madison formation; layers of limestone and other carbonates, ranging from 275-520 meters thick, and made of sediment laid down 330-340 mya when much of the western USA was the floor of a shallow, tropical ocean (map). The Madison forms many of the state’s most iconic landforms, including the Gates of the Mountains, Mission Canyon, the Lewis and Clark Caverns, and the Bighorn Canyon. The Grand Canyon’s “Redwall limestone” and the limestone that surrounds the Black Hills of South Dakota are equivalent strata. In places the Madison is especially fossiliferous. Those adventurous enough to climb Ear Mountain will be treated to an abundance of horn coral, as they walk the perimeter of the plateau.

Not your ordinary faults.
Perhaps the most fascinating aspect the Ear Mountain and the surrounding region is the way the Madison formation and other layers were deformed as these mountains were built. In response to the collision of the Pacific Plate and the North American Plate 115-50 mya, immense slabs of rock broke, and then slid up and over younger layers to their west. Mountains formed by this over-thrust faulting extend from Helena northward through Glacier Park into Alberta (called the Lewis Thrust Belt). Although this provided some of the most scenic mountains in the state, the orientation of the slabs in the 60-mile stretch between Augusta and Heart Butte (map) is especially unique. In this area thinner slabs of rock slid eastward over younger rock layers like shingles on a roof to form distinct high ridges and deep valleys that run parallel to each other as shown in this photo.

Related links:

Hiking on Top of Ear Mountain

More About the Thrust-Faulting Along "The Front"

More About the Madison Limestone

More About the Sevier Orogeny

The Madison Limestone in Montana

Thursday, January 12, 2017

Understanding Thermohaline Circulation

One of the keys to understanding ocean currents, and the "ocean conveyor belt" is realizing how temperature and salinity affect the density of water - referred to as thermohaline circulation. As water gets colder and/or saltier, it tends to sink (density current). The lab-activity shown in the video is one of our favorites at Helena High School. We call it "The Briny Deep". Students start with 800 ml of room temperature water in the tilted box, then mix various types of water (salty, cold, hot), make predictions, and then pour.

Credit for the demo goes to WARD's Science. The activity shown in the video is part of a kit that we purchased from WARD's, called "Exploring Convection". The kit also includes a second lab-activity that helps students understand the role convection plays in causing wind. Both labs come with great handouts that guide students through the activities and then follow up with questions that help them understand real-world applications.

More About Thermohaline Circulation from Wikipedia

Article About Possible Shut-Down of the Ocean Conveyor Belt

Saturday, January 7, 2017

Time to start hyping the eclipse of 2017!

This 48-second NASA video provides a view of the United States during the total solar eclipse of Aug. 21, 2017, showing the umbra (black oval), penumbra (concentric shaded ovals) and path of totality (red). This version includes images of the sun, showing its appearance in a number of locations, each oriented to the local horizon. Credit: Ernie Wright, NASA Visualization Studio

Other Eclipse Resources
1. Watch this 2.5 minute video to see how he created the animation shown in the video above.

2. Below is another 48-second video from Ernie, showing what the eclipse will look like from the Moon.

Thanks to Rick Dees (Huntley-Project High School) for showing me these resources!

Interested in hiking? Check out my Montana hiking blog at bigskywalker.com.