Geothermal Pools Explanation

We have been learning about why the water in the hot pools at Hanmer is hot and what heats it. We have done a lot of research and this is what we found out.

We are learning to write an explanation to explain a scientific
phenomenon

Hanmer Springs in the Southern alps of the South Island has natural hot pools.
The water in the hot pools at Hanmer Springs is approximately 173 years old .

The hot pools aren't heated  by mechanical heating. There is actually an underground
heating source that heats a reservoir of water 2 km’s deep under the earth surface
which makes the geothermal pools.  This is an ongoing water cycle.

The geothermal water cycle begins with the ring of fire. New Zealand is on the ring of
fire. This is an area in the basin of the pacific ocean  where many volcanic eruptions and
earthquakes happen. These happen because of the tectonic plates inside the earth
moving and colliding.

Tectonic plates are massive pieces of the earth's crust.
When they move it can cause an earthquake. Scientists believe that  every 300 years
the tectonic plates will fall apart and cause a massive earthquake. Two tectonic plates
pressing up against each other, makes the land lift into mountains like the Southern Alps
where Hanmer is. They also cause fault lines.

Fault lines are fractures in the earth's crust where rocks on either
side of the crack have slid past each other. Fault lines can be hundreds of kilometres
long like the Alpine fault underneath Hanmer and Greymouth.

Hanmer springs sits right on a fault line which means there are fractures in the rocks
from earthquakes. These fractures go down deep into the earth.  This means when it
rains or snows the water can seep through and go deep in the ground into underground
ponds. There is one under Hanmer. The water started off as snow and water which falls
on the Hanmer plains which then it travels down 2 kilometres underground to the
reservoir.

The reservoir 2km underground is then heated.  It is heated up by the earth's core.
and the tectonic plates rubbing together under the ground.  Earth’s core is thousands
of kilometres inside the earth but is extremely hot so the heat can be felt under the
earth’s crust which is where the reservoir of water is. The tectonic plates rubbing together
also produces heat which heats the water to.  This is called geothermal heating which is
heat from the earth.

The tectonic plates rubbing together also creates pressure which
pushes the water back up through the fractured rock  to the surface which then creates
the natural pools.

As the water in the pool steams it is evaporated by sun and returns to the air and the
cycle will begin again.