The
first type of geyser we will talk about is called a
fountain or pool geyser. Fountain geysers are
characterized by a pool of hot water. When the geyser is
not active, it looks just like a very deep pool of
steaming water; however, this is actually the place
where the water spews out. If you were to view the top of
the geyser when it was about to erupt (this is not
recommended), you would see the pool of water drop down into
the geyser right before it erupts. Some examples of fountain
geysers are: The Great Geyser in Iceland, Narcissusin in
Yellowstone Park, and Kotegu in Russia (Geysers).
The next type of geyser is
called a cone geyser. Cone geysers are also known as column
geysers and were named for the cone that usually forms
around the geyser's mouth. This cone is created over
hundreds, or even thousands, of years from minerals coming
out of the geyser when it erupts and building up around it.
If you look on the right
hand side of this page, you can see a picture of a famous
cone geyser "Old Faithful".
Another interesting type of
geyser is known as a cold-water geyser. This type of geyser
has a completely different method of operation as the other
types of geysers discussed so far. Cold-water geysers are
driven by CO2 dissolved in water building up inside the
geyser shaft (Glennon, 2005). Once enough gas is in the
geyser the air pressure will overcome the hydrostatic
pressure of the water causing it to erupt like a heat driven
geyser would.
The last type of
geysers (more of a subtype) we will discuss are called
perpetual spouters. These are geysers that erupt all the
time. Since they are constantly erupting they do not shoot
water and steam as high into the air as a normally geyser
would. Nevertheless, perpetual spouters do have "phases"
when they are erupting higher into the air, and times when
the eruptions are not as high. It is also possible for a
geyser to operate as a normal geyser for periods of time,
and as a perpetual spouter other times.