Volcanism and volcanic parks:

Some of the most unique and beautiful national parks are derived from old, and in some cases rather new, or least still active volcanoes. Mount Rainier, Crater Lake, Lassen, Yellowstone are found on the mainland while Haleakala, Samoa and the Hawaii Volcanoes are found further west, and further north, Aniakchak in Alaska.

Other parks with volcano features:
Bandelier National Monmument in New Mexico has 13th century cliff houses dug into volcanic tuff,
Chiricahua National Monument (AZ) highlights a maze of pedestals and spires eroded from volcanic rock,
Craters of the Moon (ID), a black landscape ( especially at night) of cones, caves and craters, and
LavaBeds, just north of Lassen (CA) full of lava tubes, flows and cinder cones, once was the hiding place of Native Americans.

These are just some examples. Many more exist, including the well known Mt. Saint Helens.

What are some of the geological characteristics common to these parks?

The majority of the above landscapes display lava tubes, lava flows or cinders.
If magma (mobile liquid rock) reaches the earth's surface before it solidifies it is called lava.
Lava may erupt quietly as in flows,
or erupt rather violently up into the air ( pyroclastic debris) coming down as pumice, cinders, ash, bombs or even as blocks.

If the lava is highly viscous with a lot of gas in it, it will explode.
A less viscous lava that releases gas as it rises the lava will flows. The gas itself is mostly steam, some hydrogen sulfide, carbon dioxide and HCl.

The viscosity of the lava is dependent on:

the concentrations of chemicals,
the water content and
temperature.

Soldier's Delight down the road is made up of mafic rock, with its'
characteristic greenish rock, and a very high ratio of Mg:Ca ( 4:1)
which causes the plants to be stunted ( not enough Ca in their diet).
It is also very porous which allows the water drain away a bit too fast.

Initial lava composition not only affects nutrients that make up the soil it produces
but also the shape the lava takes on the surface.
Mafic lavas tend to form shield volcanoes which have broad cones
built up with layers of lava.

Mauna Loa Shield Volcano, Hawaii, as seen from Mauna Kea summit

On the opposite end of the scale, very viscous felsic lava may solidify right above
the vent forming steep sided domes. These volcanoes can be very explosive, and thus
dangerous. Lassen peak is a large dome.

In between the extremes shown above we find composite cones:
Mt Rainier: Andersite& pyroclastics), or
small cones built up of cinders from local accumulations of gas ( Lassen cinder cone).

The same area can house many types of these formations, with early volcanic activity
spewing out silica rich rock, only to later give off basaltic rock.

Where are they found?

Often volcanoes are found running parallel to the boundaries of tectonic plates.
Along the west coast of the US, there is a pacific plate: the oceanic crust subducts
beneath the continental plate. The resulting heat and pressure cause rocks to melt which results
in lava which eventually makes it way up to the lands surface. Examples are Mt. Rainier, the Californian
volcanoes as well as the Alaskan cones.

Yellowstone, far from the coast, formed because it sits over a hotspot. These hotspots may reside far
below the surface in the upper mantle, and molten rock formed over these spots rises to the surface.
There are 2 theories about these hotspots ( see diagram in class). Either the heat and molten rock come from
far below, of heat a circular current high above.

Yellowstone geology:

Little less than 1/3 of the total park, the Yellowstone caldera is an enormous area of about 1500 square miles.
It extends about 40 miles long and 30 miles wide.

Studies indicate there were 3 separate volcanic events all of which occurred in the last 2.5 million years.
Catastrophic eruptions occurred here about:

2.1 million years ago, the largest of the eruptions occurred carrying 600 cubic miles to the surface ( 2,400 times the size of Mt. Helens
a second one 1.3 million years ago, erupting 67 cubic miles of material and
then 640,000 years ago carrying 240 cubic miles of material.

During each event enormous amounts of lava came up building thousands
of feet of ash, breccia, tuff and lava layers. Smaller eruptions have continued to occur till 70,000 years ago.

http://www.cotf.edu/ete/modules/volcanoes/vyelupliftmap.html

A Caldera is a large depression commonly formed by collapse of the ground following explosive eruption of a large body of stored magma.It is thought that these massive eruptions withdrew so much lava, that the roof of dome collapsed under its own weight. The original materials was probably remelted to make up the new layer.

 

Situation Now:

Heat energy normally flows from warmer to cooler areas. However in Yellowstone the flow of heat from below
is 30 times the average rate of heat flow from below.
Just 500-600 feet below, the temperature is over 400 F.

In the last decade, research has shown that two volcanic vents, now known as "resurgent domes", are rising again. Annually, they either rise or fall, with an average net uplift of about one inch per year. During the period between 1923 and 1985, the Sour Creek Dome was rising. In the years since 1986, it has either declined or remained the same.

http://www.cotf.edu/ete/modules/volcanoes/vyelupliftmap.html

The second most noted feature in Yellowstone: Hydrothermal Features:

Geysers, fumaroles (also called solfataras), and hot springs are generally found in regions of young volcanic activity.
Half of all the geysers that exist in the world are within the boundaries of Yellowstone National Park.
Over four hundred geysers exist in the United States' first national park.

Surface water ( in great supply here from mountain runoff) percolates downward through the rocks below the Earth's surface to high-temperature regions surrounding a magma reservoir, either active or recently solidified but still hot.

The cold water is heated by hot brine.

The water temperature rises above the boiling point but cannot escape as steam as it is held underpressure by the rocks above it.

It then becomes superheated rising to temperatures of 400 F.
As we know hot water is less dense the cold water, and rises back to the surface along fissures and cracks.

As it rises along cracks and fissures it dissolves silica in the rock. Some of these silica will start to coat the fissures to form a near pressure tight seal. The pressure of the heated water is held and can build as it is now bound by this 'glass' lined plumbing system.

At the surface the silica can precipitate out to form geyserite cones or the scalloped edges of hot pools.

Erupting geysers Large amounts of hot water are presumed to fill underground cavities. The water, upon further heating, is violently ejected when a portion of its suddenly flashes into steam. This cycle can be repeated with remarkable regularity, as for example, Old Faithful Geyser in Yellowstone National Park, which has erupted on an average of about once every 90 minutes.

Geysers function like a pressure cooker. The water within the plumbing system is hotter than boiling, but "stable" because of the pressure exerted by all the water lying above it. (Remember that the boiling point of a liquid is dependent upon the pressure. The boiling point of pure water 212 degrees Fahrenheit (100 degrees Celsius) at sea level. In Yellowstone the elevation is about 7,500 feet, the pressure is lower, and the boiling point of water is only about 199 degrees Fahrenheit (93 degrees Celsius).

The filling and heating process continues until the geyser is full or nearly full of water. A very small geyser may take but a few seconds to fill whereas some of the larger geysers take several days.

Because the water of the entire plumbing system has been heated to boiling, the rising steam bubbles no longer collapse near the surface. Instead, as more very hot water enters the geyser at great depth, even more and larger steam bubbles form and rise toward the surface. At first, they are able to make it all the way to the top of the plumbing system. But a time will come when there are so many steam bubbles that they can no longer simply float upwards. Somewhere they encounter some sort of constriction or bend in the plumbing. To get by they must push through the narrow spot. This forces some water ahead of them and up and out of the geyser. This initial loss of water reduces the pressure at depth, lowering the boiling point of water already hot enough to boil. More water boils, forming more steam. Soon there is a virtual explosion as the steam expands to over 1,500 times its original, liquid volume. The boiling rapidly becomes violent and water is ejected so rapidly that it is thrown into the air.
The eruption will continue until either the water is used up or the temperature drops below boiling. Once an eruption has ended. the entire process of filling, heating, and boiling will be repeated, leading to another eruption.

Fumaroles, which emit mixtures of steam and other gases, are fed by conduits that pass through the water table before reaching the surface of the ground. Hydrogen sulfide (H2S), one of the typical gases issuing from fumaroles, readily oxidizes to sulfuric acid and native sulfur. This accounts for the intense chemical activity and brightly colored rocks in many thermal areas.

The hottest of Yellowstone's geothermal features are steam vents (fumaroles).  Black Growler Steam Vent, on the hillside , has measured 199 to 280 degrees F (93 to 138 degrees C).  A plentiful water supply would help cool these features; however, steam vents are usually found on hillsides or higher ground, above the basin's water supply.  They rapidly boil away what little water they contain, releasing steam and other gases forcefully from underground.
Photograph by R.L. Christiansen on 27 July 1973

Hot springs occur in many thermal areas where the surface of the Earth intersects the water table. The temperature and rate of discharge of hot springs depend on factors such as the rate at which water circulates through the system of underground channelways, the amount of heat supplied at depth, and the extent of dilution of the heated water by cool ground water near the surface.

There is no constriction which would allow the build up of intense pressure, so the hot water moves up, colder down. A convection current occurs.

Mammoth Hot Springs:

 

At Mammoth Hot Springs, hot water ascends through the ancient limestone deposits of the area( instead of the silica-rich lava flows). As ground water seeps slowly downward and laterally, it comes in contact with hot gases charged with carbon dioxide rising from the magma chamber.

Some carbon dioxide is readily dissolved in the hot water to form a weak carbonic acid solution. This hot, acidic solution dissolves great quantities of limestone as it works up through the rock layers to the surface hot springs.

Once exposed to the open air, some of the carbon dioxide escapes from solution. As this happens, limestone can no longer remain in solution. A solid mineral reforms and is deposited as the travertine that forms the terraces.

 

Mudpots: a biological conversion

Where hot water is limited and hydrogen sulfide gas is present (emitting the "rotten egg" smell common to thermal areas), sulfuric acid is generated.

The actual conversion is due to bacteria converting the sulfur ( H2S - reduced form to an oxidized lower energy state H2SO4 or sulfuric acid.

The acid dissolves the surrounding rock into fine particles of silica and clay that mix with what little water there is to form the seething and bubbling mudpots.

Magnificent Colors:

The colors one can see in the hot springs is incredible. This coloration is due to several factors:

Light refraction,
Suspended minerals,
Microscopic organisms: algae, bacteria and Archaea -some of who ancestors lived on earth 4 Billion years ago.

After water cools down below 160 F, many of these organisms can colonize the waters:
Blue-green bacteria grow in alkaline water:

They were one of the earliest of the photosynthesizing bacteria, forming oxygen which eventually escaped to form the protective ozone layer above us, as well as fixing nitrogen, making it available for themselves and other life forms eventually.

In acidic hydrothermal pools, algae grow:
Cyanidium = neon green mates or Zygogonium= purple mats. in addition to
Minerals: sulfur=yellow + iron, arsenic= red, orange , black + sinter ( hydrated form of silica) = gray

In neutral areas algae such as Phormidium ( orange shag areas), Synechoccus and Choroflexus = yellow or yellow-green and still others form banding patterns.

Bioprospecting:
1966: Thermus aquaticus was identified: in 1985 an enzyme it produces ( taq) ( now synthetically produced) contributed to the DNA fingerprinting process that has earned hundreds of millions of dollars for the patent holder ( but nothing for the park where it originated)
1997 the park signed an agreement with Diversa Corp. so that a portion of their findings that is financially lucrative goes back to the park for preservation. 1999:legal suite 'til EAS done. Researchers feel that 99% of species have yet to be identified. Organisms have been found so far that would: can produce ethanol under extreme conditions; treat ag food waste; bioremediate hydrochlorine products; recover oil; improve animal feed and detergents etc.

Grand Canyon of the Yellowstone River:

The specifics of the geology of the canyon are not well understood, except that it is an erosional feature rather than the result of glaciation. After the caldera eruption of about 640,000 years ago, the area was covered by a series of lava flows. The area was also faulted by the doming action of the caldera before the eruption. The site of the present canyon, as well as any previous canyons, was probably the result of this faulting, which allowed erosion to proceed at an accelerated rate. The area was also covered by the glaciers that followed the volcanic activity. Glacial deposits probably filled the canyon at one time, but have since been eroded away, leaving little or no evidence of their presence.

Biology of Yellowstone:

Vegetation: Many types of vegetation can be found here dependent on ppt and soil type.

In the driest of the areas we find sagebrush/steppe with rain only in the range of 15-20" /year. Here sagebrush found in the dry areas of Utah, Colorado and further west comingle with grass, shrubs and forbs.

Lodgepole pine forest dominates areas of the park underlain with rhyolite. Few other trees can grow except as young trees in their understory ( shade intolerant) . They make up 80% of the trees in the park
This soil is poor with Al, K, Na -oxides. The area around old Faithful has much of this type of vegetation. This species dominates recently burnt areas. Produce both serotonous and non-serotinous cones. Up to 75 ft. History: used by NA natives for their lodges.
Like disturbed soils w/hi mineral content. Shallow root systems good for shallow soils found here but bad in windstorms. Decay at only 1% per year so can last 100 years dead.

Up on the hills/mts where andesitic rock ( the intermediate type of grey rock) is more prevalent along with more rain/snow , Spruce-fir can grow. Englemann spruce and Sub-alpine fir
Englemann spruce 60-120 ft high; 350-500 years old.Actually prefer shade; will live under lodgepole.
Subalpine only true fir: eaten by moose and other ungulates.shade tolerant.

Way up the mountains, we run into subalpine/alpine vegetation which we will cover later. Whitebark pine gives way to tussoky small alpine vegetation. White bark grows 7000 to 10000 ft; only 49 ft high, Few mature cones as prized by squirrels, Clark's nutcrackers, bears.

Aspen can be found scattered in the N. Range and along some of the rivers.

Problems: Exotic invasions: 195 exotic species now found some which may be able to outcompete endemics. Some of the worse are 4 Knapweed species. These very aggressive species can form a monoculture, taking over the grasses which feed many of the herbivores.

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Animals:

Home to the largest concentration of mammals in the lower 48:
60 different mammals live here:
Bears: black ( 500-650) + grizzly: 280-610
Gray wolves were reintroduced in 1995 - 100 now
Seven native ungulates: elk, mule deer, bison, moose, bighorn sheep, pronghorn and white-tailed deer. Includes one of the largest elk populations in the US.
Non-native mountain goats maybe colonizing the park.

Bison: 3,500 animals: average life span 12-15 years: males 2000 lbs, females 1000 lbs. Aggressive, agile and can run up to 30 mi/hr. eat grasses and sedges; can be killed by wolves but few are.
Estimate between 30-60 million in 1800's in NA. Roamed from Pacific to Appalachia. Disappeared on east coast already by 1832. Herds in grasslands were 3-5 million each.. The only place where they were protected was in Yellowstone by the army, but even here only a two dozen free ranging animals survived. From this stock and from purchases made from private stock, the thousands that now exist originate.

Problems with Brucellosis:

About 50% of the parks bison test positive for Brucellosis exposure ( though only half of these may actually carry the bacteria) , a disease that can cause susceptible domestic cattle to abort their first calf. Because the free ranging bison can migrate into Montana, their exposure to cattle in to the state concerns the cattle industry there. The disease can be transmitted only by females ( exposure to birth materials)

Bison probably contacted the disease from cows brought into the park in the early century for food. The disease does not appear to negatively impact the bison. Cattle normally get this disease from other cattle. A vaccine used successfully in cattle does not work in bison. There is no known wild case of transmittal from bison to cattle, but because the state has spent much money in eradicating the disease they do not want any of the bison in the state. A single diseased animal in a herd of cattle will condemn the whole herd so the financial stakes here are high. Elk also carry the disease and may infect the bison.

Problems arise when the winter is bad, and bison migrate into Montana, where they were allowed to slaughtered if found seriopositive. In 1988 569 animals were shot: in 1996,a bad winter year 1084 animals were killed. The following 2 years were milder and less animals were killed. However the case went to court and finally negotiations have been reached to test trial some limited migration of buffalo, more vaccinations and better management of buffalo. At this time though animals can still be killed under certain conditions.

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Fire ecology:

Fires have always appeared periodically in Yellowstone ( practically true for all the west). Where there is Douglas fir, fire would occur 25-60 year intervals. In Lodgepole area, fires cycle every 200+.

Lightning strikes at least 22 per year.
This is a typical fire adapted system, and fire is necessary to maintain the grassy areas as well as the Lodgepole pines.

Previously, fire was suppressed as early as 1885 by the army that helped start the preservation process till 1972 when it was decided that fires could run their course in this wilderness area.
Between 1972 and 1988:

Tens of thousands of lightning strikes simply fizzled;
140 lightning-fires were small in scope:
More than 80% of the fires went out by themselves:
No significant damage was done overall to humans.

At this point, natural fires which do not threaten human life or important structures may burn. In some case prescribed burning may be necessary.

Fire of 1988:

A dry summer lead to super dry conditions:
About 36% of the park was affected but not destroyed.
About 50% of the areas affected were hit by fires started outside the park:
It cost the govt. $120 million dollars to fight
After it burnt out in the fall, biological assessment showed that only 10% of the seeds were burnt up so regeneration was rapid, and few animals died.
Although there has been some decline of moose habitat ( less moose) other animals have found enough to eat,
More of a problem was the drought which caused the fire, and the bad winter following.