Maths News: Volcano Survivor 1

Kilauea erupts in Hawaii MAY 2018.

The amazing maths of volcano eruptions.

Can you out run a lava flow?

In every volcano disaster movie from Volcano (1997) with Tommy Lee Jones to Dante’s Peak (1997) with Pierce Brosnan someone somewhere tries to out run a lava flow.

Is this possible? (See movie cliché busted by maths here.)

Now a lava flow from Hawaii’s Kilauea volcano is threatening tiny town of Pahoa, Hawaii again. (below).

You will find excellent information about the Kilauea and other volcanoes at the

US Geological Survey here.

How to stop lava?

As the temperature of lava exceeds 1000⁰ C there are very few ways to stop lava. According to the Taylor Kate Brown SMH (10 SEPT 2014) options include:

Bombing

Blasting (it with cold water)

Barricading it

Or adding concrete.

What if you are on your own.

Can you out run lava?

Lets do the maths.

Lava from Kilauea travels 17 yards per hour so the lava velocity is:

V_L =   17 yds/hour = 15.5 metres /hour

(See Vox.com)

Maths News: Volcano Survivor 2

Kilauea erupts in Hawaii MAY 2018.

The amazing maths of volcano eruptions.

Once lava flows are established new RIVERLETS can run on top of the original lava flow at great speed.

The fastest Lava flows recorded were in Hawaii in 1950 when Mauna Loa erupted. The lava traveled at 6 miles (10 kilometers) per hour through thick forest. But once the lava flows became established and good channels developed, the lava in the channels was flowing at up to 60 miles/hour (97 kph)

Can you out run a lava flow?

You are 2 km from the volcano rim and start running.

V_L =   97 kph = 1.6 km per minute (k/min)

     =   60 mph

V_H = 18 kph = 0.3 km/min

   = 11.2 mph (miles per hr )

GRAPH:

How long will it take for the lava to catch you?

 

SIMULTANEOUS EQNS:

How long will it take for the lava to catch you?

Maths News: Volcano Survivor 3

Kilauea erupts in Hawaii MAY 2018.

The amazing maths of volcano eruptions.

One of the greatest dangers in a volcano eruption is not the lava flow OR being hit by a lump of flying lava or rock, but by being choked by the fast moving scorching hot pyroclastic cloud.

In 1991 pyroclastic cloud blew out of the side of Mount Unzen in Japan. NASA has an excellent diagrams for such an event here.

According to the NASA website:

Highly mobile, these flows reach velocities of up to 400 kilometers (250 miles) per hour and can spread as far as 100 kilometers (60 miles) from the eruption point.

Can you out run a pyroclastic cloud?

Here is what happened in 1991 when the pyroclastic cloud blew out of the side of Mount Unzen in Japan.