Volcanoes and Earthquakes Lecture Notes

Impacts of a Supervolcano Eruption on People

The greatest danger would be within 1,000km of the blast, where almost everyone would be killed.
If a supervolcano eruption happened at Yellowstone, the USA would be the worst affected.
Ash is one of the most dangerous substances that erupts from a volcano.
Volcanic ash particles are not smooth; under a microscope, they are jagged.
An estimated 90,000 people might die from inhaling ash, which forms a cement-like mixture in human lungs.
Even the east coast could be immobilized by just 1cm of ash.
Many buildings would be destroyed near Yellowstone, as it only takes 30cm of dry ash to cause a roof to collapse.
Water supplies would become undrinkable.
Ash would clog up air filters on all vehicles from cars to aeroplanes, disrupting transport across the USA for weeks.
Air travel to and from the USA would be badly affected, causing major disruption in other countries and to businesses.

A Yellowstone eruption would inject 2,000 million tonnes of sulphur high above the earth's surface.
It would take 2 to 3 weeks for the resulting sulphuric acid aerosols to cloak the globe.
These aerosols reflect sunlight, reducing the amount of energy reaching the lower atmosphere and the Earth's surface, cooling them.
Global annual average temperatures would drop by up to 10 degrees Celsius.
The northern hemisphere could cool by up to 12 degrees Celsius.
Such a dramatic drop in temperature could mean crop failures and a return to the 'Little Ice Age' conditions seen in Europe during the late 1600s.
Locally, 67 species of mammals that live in Yellowstone National Park, including Bison and wolves, would most certainly die, disrupting the local ecosystem for decades.
It is at least 10 years before any vegetation becomes re-established in the areas close to a super eruption.
Acid rain would occur.
Unusual weather patterns, e.g., purple fog, increased rainfall, and flooding, could occur.
Spectacular sunsets could result.
There would be a loss of vegetation.
There would be a decrease in productivity and life.
There would be interruption to food businesses.

Improve construction methods to make builds even more earthquake-proof.
The government provided over 23 trillion Yen over 10 years to aid rebuilding programs and still improve standard building.
Small buildings must have reinforced frames of concrete.
Homes are not allowed to be built from wood.

Older buildings remain a problem as they are likely to collapse in the next strong quake.

The new regulations should reduce injuries and loss of life in a major EQ, which will remain upright.

More money is being spent on a massive network of ocean floor sensors and tidal gauges to prevent miscalculation.
The 5th of November is preparedness day for tsunami drills.
Practicing the population drills is now officially Japanese.
Sensors being placed on sea floors would save lives.

Dash 36, 40

This won't protect from waves as occurred in previous regions during this event.

While this may save some lives in smaller EQ events in the future, they are unlikely to be effective if a similar-sized event occurs.

In the Great Tohoku earthquake in 2011, the 12m tall tsunami sea defenses were easily overtopped by 40m high in some coastal locations. Since then, the authorities have worked to improve the sea walls by making them taller and stronger, particularly around nuclear power stations. However, the new walls are only built to be 18 meters high. A powerful tsunami like the one that struck in 2011 could easily overwhelm these new defenses. They will protect the coast against smaller tsunamis but are unlikely to be effective if another magnitude 9.0 affects the region.

Volcanoes are mountains, often cone-shaped, that are formed by surface eruptions of magma.

Features: Crater (if filled with water, a crater lake is formed), Fumarole, Cone, Lava, Vent, Side vent, Ash, Central vent.

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