Later eruptions

• Eruptions Global• Eruptions Local

Jomon period

• Four big eruptions• Lots of stones• Ash• Both east and west

Gotemba Mud Flow

Looking back about 2,300 years

It’s a pretty big area

A bit of mud

No problem

Healthy?

Think again

Huge

Fast-moving

Destructive

The east face collapsed

Huge mud flow

Huge area destroyed

Mud flows are not good

They can be very, very bad

Before and after

Mount Pinatubo, Philippines

15th June, 1991

6 meters of mud

Only 6 people killed by the eruption

Mud killed 1500 people

Nevada del Ruiz, Colombia

1985, mud flow killed 20,000 people

What causes it?

• Heavy rainfall• Lake bursts• Snow melting• Glaciers melting

Spirit Lake, Washington State

Spirit Lake after the eruption, October 1980

Mudflow

Mudflow in brown

Gotemba mudflow

Like this?

It would definitely interfere with our lives

In a big way

Let’s fast forward

Jougan eruption

• Jougan era• AD 859• To • AD 878• AD 869 – huge earthquake and tsunami• Devastates the coastal area near Sendai

At this time …

… it seems …

… there was just one huge lake here

… Not these three, Saiko, Shojiko, and Motosuko

Take a look at these sea level figures

Yamanakako is high up and shallow

Kawaguchiko is low down and shallow

The other three have different depths

But look – the same height!

Why is that?

AD 864 – huge eruption

• Gigantic eruption on the north side• Lots of lava• Eruption lasted 10 days• Ash thrown into Tokyo Bay• Some of the lava flowed into the giant

Senoumi Lake• Split it up

Aokigahara Lava flow

• This huge lava flow is now covered by a gigantic forest

• The Aokigahara forest• The sea of trees• 青木ヶ原樹海

Aokigahara Forest

The sea of trees

Aokigahara and Saiko

The forest floor is volcanic rock and soil

Very, very quiet

Easy to get lost

Difficult to find your way out

And it’s now the subject of a movie

Although people say it’s not very good!

Any publicity is good publicity

And people like creepy stories

So more tourists will probably come

There was a book

1960

Probably a long tradition

A place to abandon the old (or very young)

Strong ghost connection

Maybe you shouldn’t go there

If you are chicken, like me

Too creepy

Too creepy for me

Aokigahara is the second most popular …

World suicide location

After the Golden Gate Bridge

San Francisco

Aokigahara is definitely creepier

Not creepy at all

Anyway, fast forward

1707

Biggest earthquake in Japan’s history

At least until 2011

Followed by a huge eruption

About seven weeks later

That created this crater

Sent ash and dust as far as Tokyo and beyond

1707 earthquake

• October 28th

• The Fuji eruption?• December 16th

• Is there a connection?• Maybe

1707 earthquake

• Magnitude 8.6

• Great Kanto earthquake (1923)• Magnitude 7.9

• 2011 earthquake?• Magnitude 9.0

Great Kanto Earthquake

Asakusa

Marunouchi

Yokohama

Maybe our houses will stand up a lot better today

But don’t forget

There could be mud

Which might be more of a problem

And don’t forget

In the ninth century

Lava flow was so monumental …

It split up a huge lake

And created a huge forest!

What can we do?!

Let’s keep praying