Hotsprings, A Steamy Subject ...
Where does the spring water come from?
Most of the rain and snow that falls on the slopes of a mountain ends up in
rivers and streams. Some of it, however, filters down through the cracks and
pores in the mountain rock, pulled by gravity to a depth of three kilometres
below the surface. It is this water which later returns to the surface in our
hot springs.
Why is it warm?
As it seeps into the ground, the water becomes hotter and hotter — heated by
radioactive decay in the earth's core. When the water boils, pressure forces it
upward, just like the water in a coffee percolator. The speed at which the water
rises, and the degree to which it mixes with cold ground water, causes the
temperature to fluctuate.
Where does the odor come from?
As the water heats up, it dissolves minerals in the surrounding rock. When these
dissolved minerals break down, they release hydrogen sulphide gas, which smells
like rotten eggs. Pyrite and gypsum are two common sulphur-bearing minerals
dissolved in the Banff and Miette hot springs. The water at Radium Hot Springs
is odorless because of the type of rock in that area. What is tufa?
(pronounced too-fa)
As the hot springs water bubbles from its underground channel, it begins to drop
the load of minerals it gained on its journey through the earth. One of these
minerals, calcium carbonate, hardens into a porous grey/brown rock called tufa.
The entire hillside around each springs is composed of tufa.
