Wednesday, May 19, 2010

YELLOWSTONE NATIONAL PARK





In this post we are going to discover some interesting facts about First National Park in the World, Yellowstone National Park was established in 1872. I am going to focus on hydrothermal features that occur in this park.
In the first part, I will write about general information about geography and geology to understand why the hydrothermal features happen in Yellowstone. Then, in the second part, I am going to explain different types of these features. Finally, I will show you two examples: Old Faithful geyser an Prismatic hot spring.
Before starting I would like to ask you something:
Yellowstone was named after:
a) the color of the rocks is yellow
b) the translation of the Minnetaree name Mi-ts-a-da-zi
c) yellow was the favourite color of Ulyses S Grant, president of USA.
Now you can find out the answer in the next picture.

GEOGRAPHY AND GEOLOGY
 More or less he 96% of the land of the area is located within the state of Wyoming, norhtwest of Wyoming, another 3% in Montana and 1 % in Idaho. It spands an area of 8/980 km2, the same area as the province of Almeria.
And what is the most important feature in Yellowstone?
The most important feature in  that it is located in a supervolcano. Supervolcano has erupted with tremendous force several times in the las two millions years. Volcanic rocks cover most of the land of Yellowstone.

We can see the caldera boundary in the map, the caldera is the crater of  supervolcano, and we can see the rivers like Yellowstone, Snake, Firehole... and the lake.
Now we have the caldera and  water...
And what happen when the water reachs the caldera?
The joint of the water and hot rocks produce HYDROTHERMAL FEATURES.
We have four types of Thermal Features:
GEYSER, HOT SPRING, MUD POT  and  FUMAROLE.
Now I am going to explain one by one.

For geyser to occur there must be three things:
heat
water
plumbing system
Magma chamber provides the heat, which radiates into surrounding rocks.
Water rain and snow go into underground through cracks in the rocks.
As water reaches hot rock it begins to rise back to the surface. The hot water dissolves the rock creating geyser's plumbing systen. When the hot water can not resist the pressure, hot water and steam spray out of the geyser's surface vent. It works like a pressure cooker.

Hot springs don't have constricted plumbing system, and we see a colorful pool on the surface.
Mud pot is a pool with bubbles of mud. The mud is generally of white to grayish color. They smell like "rotten egg'', it is due to sulfuric acid. The acid dissolves the surrounding rocks into fine particles.


Fumaroles, or steam vents, are hot springs with a lot of heat, but so little water that it all boils away before reaching the surface.

EXAMPLES
OLD FAITHFUL GEYSER is the most popular one in Yellowstone. The average heigh of an eruption is 44 meters. Intervals between eruptions can range from 1 or 2 hours.
In the next picture of PRISMATIC HOT SPRING we can see beautiful colors, why?
The blue color is due to sunlight being scattered by fine particles suspended in the water. Yellow, orange and brown colors are caused by THERMOPHILES, heat-loving microorganism. This microbe contains colorful pigments that allow them to make energy from sunlight and live in the sever conditions of hot springs.

I hope you enjoy this post.






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