Showing posts with label Geology. Show all posts
Showing posts with label Geology. Show all posts

Saturday, July 16, 2016

Yellowstone's Morning Glory Pool

The pool has barely retained its blue color.
Photo by Miguel Hermoso Cuesta

Yellowstone National Park is home to some of the most amazing natural sights in the world, not least of which is the Morning Glory Pool. The Morning Glory Pool is a hot spring that attracts quite a few visitors. It is known for its vibrant color.  However, much of that has diminished over the past decades. Nonetheless, the pool is still stunning to behold. The change in the pool’s color is also very interesting in that it gives us a first hand look at the effect that pollution can have on the world that surrounds us.

The Morning Glory Pool is located on the northern edge of the Upper Geyser Basin. It was named in 1883 for its magnificently deep blue color that nearly matched the flower for which it was named.

This pool is roughly 23 feet by 26 feet and is about 23 feet deep. Currently, the temperature of the water in the Morning Glory Pool is around 171.6 degrees Fahrenheit. The water is clear enough that you can see the way that the sides taper down into its depths. Viewed from some angles, this gives the illusion that the pool is in fact running down into the center. This also makes the pool seem as if it has a “stem,” which makes its name that much more appropriate.

Unfortunately, the pool has changed color over the years because of the acts of uncaring or unwitting visitors. Tons (yes, tons) of trash have been thrown into the pool, effectively blocking the vents that keep the pool so hot. Thermophilic bacteria that need high temperatures to survive cause the blue color of the pool.

When the vents became blocked by trash, the temperature in the pool started to drop, thus killing some of these bacteria. The drop in temperature also made it possible for other bacteria to thrive in the Morning Glory Pool. These new bacteria are red, yellow and orange and are changing the pool’s color from the outside in. As the pool gets cooler, the new bacteria move closer to its center. Given enough time, the entire pool could change if the vents do not get opened back up.

An old road used to go directly by the Morning Glory Pool, so there were many more visitors to it in the past. Today that road is gone. Visitors must walk or bicycle for 1.5 miles both ways to get to the pool; a three-mile trip total. This means fewer visitors and fewer opportunities to steal pieces of the edge of the pool or throw trash into its depths.

Because the Morning Glory Pool is a geyser it is hoped that it will one day blow the trash loose and thus remove the blockage from its thermal vents. However, whether it will do so or not is uncertain, especially with the amount of trash that is in it. For now, we can only hope that some effort on our part or some natural occurrence will return the pool to its original, magnificent state.

Wednesday, March 23, 2016

The Moeraki Boulders of Koekohe Beach


Moeraki Boulders
The Moeraki Boulders
Moeraki Boulders are just one of the many naturally occurring oddities that are found on Koekohe Beach and surrounding areas in New Zealand. Some have likened the appearance of these boulders to the bowling balls of giants, who have long since abandoned their game. In a way, they do look like bowling balls because some of them are nearly perfectly spherical. This sort of boulder occurs naturally elsewhere, but the number of them in the area and the beauty of the surrounding New Zealand landscape seems to draw people to the Moeraki Boulders in particular.

Roughly 56 million years ago (during the Paleocene Epoch), small bits of wood, fossils and bones on the bottom of the ancient sea floor began to accumulate layers in what is now New Zealand. Over time, these small formations grew larger and larger in much the same way an oyster's pearl grows in size. The large, round stones that resulted from this process are known as septarian concretions. They eventually became trapped in the stunning sheer cliffs that grace the coast of Kohekohe Beach between Moeraki and Hampden, New Zealand.

When erosion began to take its toll on the cliffs, the ancient Moeraki Boulders were freed. Today, they are scattered across the landscape like errant marbles. Some are not spherical, but are oval instead. These Moeraki Boulders look like dinosaur eggs–really big ones, at that. Some of them have cracked open and revealed their softer, eroded interior. Some of these are big enough for a man to sit in, giving the appearance that he has just been hatched from the ancient stone. The biggest of the Moeraki Boulders is close to nine feet in diameter and weighs several tons.

The surfaces of the Moeraki Boulders are cracked, causing them to look like turtle shells. The reason for this cracking is yet unknown to science. We do know that the interiors of the boulders are weaker than the exteriors, yet the exteriors are cracked. Some of the boulders are much smaller than others. The cracked surface makes them look like large turtles half-buried in the sand.

An 1848 drawing by W.B.D. Mantell shows the Koekohe Beach with more of the Moeraki Boulders than are currently there, so we know they are slowly vanishing. However, more are still trapped in the cliffs, as evidenced by those that are only half-exposed today. There is no telling how many of them are still waiting to be revealed.

Sources

De Hek, Danny, retrieved 10/28/10, newzealandnz.co.nz/destinations/moeraki.html

Facts about Moeraki Boulders, retrieved 10/28/10, moeraki-boulders-facts.php

Evans, RJ, The Mysterious Moeraki Boulders, kuiositas.com/2010/09/mysterious-moeraki-boulders.html

Sunday, March 13, 2016

Interesting Facts About Iceland's Volcanoes

Fire spewing out of Eyjafjallajokull
during the 2010 eruptions
Courtesy of Ulrich Latzenhofer
Iceland and its volcanoes have been in the news a lot in the past few years. The Eyjafjallajokull volcano in Iceland was been very active in March and April of 2010. The ash spewing forth from this volcano resulted in the grounding of flights as far away as England, due to the danger it presents to airplanes. Prior to this tantrum, the Eyjafjallajokull volcano had not erupted for nearly 200 years. All of this attention serves to remind us that Iceland is a land of many volcanoes, some of which can have global consequences should they erupt. With that in mind, here are a few facts about Iceland's volcanoes that can give us an idea of what goes on there in the "land of fire and ice."

Hawaii gets a lot of attention for its volcanoes. This is because it was formed by volcanoes. Evidence of their activity is present everywhere there. Nonetheless, there are only two active volcanoes in the State of Hawaii. Iceland has between 20 and 30 active volcanoes. That is more active volcanoes than any other place on Earth.

The most active volcano in Iceland is Hekla. Hekla has an elevation of 4,892 feet. It is a stratovolcano that is located in southern Iceland. Hekla has erupted roughly once every ten years for the past fifty years. A Hekla eruption can come on with little to no warning and can last for weeks or months. Hekla was less active in the past fifty years. However, for some time, there was hardly a century that passed without at least one eruption from Hekla.

Iceland was formed from volcanic activity, like Hawaii. The American and Eurasian tectonic plate boundary goes through Iceland. The two plates pull apart, making it easy for lava to push through the gap. This is how Iceland was formed and why it has so many active volcanoes today.

In the past 500 years, nearly one-third of the Earth's lava output has spewed forth in Iceland. Furthermore, 83% of the world's sub glacial eruptions have occurred in Iceland. To put that into perspective, the area of Iceland is 39,707 square miles of land. The entire Earth has roughly 57,393,000 square miles of land area. Iceland is sure pumping out a lot of lava for such a small portion of the Earth.

From the above, you can clearly see why Iceland is called the "land of ice and fire." Of course, given its position on this Earth, there is a lot of ice in Iceland. However, residents can warm up by taking a dip in the large number of the geothermal spas there. Despite the scary number of active volcanoes, Iceland is easily one of the most beautiful and interesting places on Earth.

Sources

Volcanology Highlights, retrieved 4/16/10, volcano.si.edu/world/region.cfm?rnum=17&rpage=highlights

Volcanoes in Iceland, retrieved 4/16/10, kwintessential.co.uk/articles/article/Iceland?Volcanoes-in-Iceland/538

Seach, John, Hekla Volcano, retrieved 4/16/10, volcanolive.com.hekla.html



Friday, February 5, 2016

Mud Volcanoes

Chabahar Mud Volcano
Photo by Amirhossein Nikroo
Mud volcanoes are a less terrifying, but still dangerous cousin of magma volcanoes. They are also known as sedimentary volcanoes and gas-oil volcanoes. These volcanoes occur where there are deep deposits of gas and oil beneath the surface. There seems to be a connection with fault lines as well. Like magma volcanoes, mud volcanoes have dormant and active phases. During their active phases, they do not spew liquid hot rock and ash while causing massive earthquakes and lightning storms, but they are capable of spewing fire and enough mud at such a rate to displace or even kill human beings.

If you want to see a mud volcano, Azerbaijan in Eurasia is the place to go. There are no active magma volcanoes in the area, but there are hundreds of mud volcanoes. In fact, Azerbaijan has most of the mud volcanoes on the planet–more than half. However, most of the mud volcanoes there only emit small amounts of cool mud and gases. They can be between 16 feet and 1,640 feet tall. People do not live close enough to them to be affected by active mud volcanoes in Azerbaijan, but that is not the case in other parts of the world.

In 2006, a mud volcano became a problem in a residential area of Sidoarjo, Indonesia. The volcano appeared, erupted and the resulting mudflow killed thirteen people. Thousands have been forced from their homes by what has become known as the Lusi Mud Flow. The mudflow continues to this day. Interestingly, this extraordinarily large and dangerous mud volcano may not be a natural occurrence. Researchers have reason to believe that a local gas exploration well caused the volcano. Somehow, the pressure created led to a vent opening up and pouring excessive amounts of mud into the area.

There is still a lot to learn about mud volcanoes. They have not been studies as extensively as their noisy and deadly cousins have. We do know that built up pressure beneath the surface is involved in the birth of mud vents. We also know that they do not cause as much damage as magma volcanoes, though they can produce earthquakes and balls of fire. Because it appears they can be triggered by careless drilling, there will doubtless be much more research into what exactly causes them and how we humans can avoid being one of these causes.

Sources


Mud Volcanoes in Azerbaijan, retrieved 12/29/10, azerb.com/azmud_volcanoes.htm