History Snippets: Mt. St. Helens

“History Snippets” serializes small bits of research from an unfinished test project. The theme is technology and natural events that shaped our modern world.

Mt. St. Helens 1980

Mt. St. Helens, 1980. Volcano. This photograph is credited to the National Geographic. A modern natural disaster which killed 57 people, few deaths for a volcano owing to its remoteness and a little early warning detection.

In a heavily populated area, this same eruption, small as volcanoes go, could have been catastrophic. An 83-year old resident named Harry R. Truman lived on the far end of Spirit Lake and refused to be evacuated. The explosion blew 1,200 feet of rock off the top of the mountain. They say Mr. Truman had 16 seconds before the superheated pyroclastic flow rolled over him; they never found Mr. Truman’s body. It was the biggest eruption in the 200+ year history of the political body called the United States. Due to the pillar of ash and smoke, one cannot see the actual mountain in the 1980 photo.  Below, the mountain is shown 28 years after the eruption, in the photo below.

Mt. St. Helens 2008. Photo by Alex Forbes.

Mt. St. Helens, 2008. Volcano crater. I captured this view on a flight to Seattle along the Cascade Range. You can see part of the crater blow-out and the shrunken Spirit Lake, which, surprisingly, recovered its fish and plant species within a few years. Atmospheric haze is due to the vast California forest fires in the month the photo was taken.

Volcanic Disaster Scales

The image below is a scaled-down image capture of a free PDF available online from Sky & Telescope magazine, “REAL Disasters” by editor in chief Robert Naeye. The PDF is available in the editors’ article “The Great 2012 Scare“.

Scaling historic volcanoes and supervolcanoes. See article text for links to the original Sky & Telescope article and PDF.

Scaling historic volcanoes and supervolcanoes. See article text for links to the original Sky & Telescope article and PDF.

  • Mt. St. Helens is represented by the top cube, 1980, 0.24 cubic miles of ejecta
  • Mt. Pinatubo, 1991, 2.4 cubic miles
  • Krakatoa, 1883, 4.3 cubic miles
  • Mount Mazuma (Crater Lake), 7,700 years ago, 18 cubic miles
  • Tambora, 1815, 36 cubic miles
  • Yellowstone caldera, 1.3 million years ago, 67 cubic miles
  • Yellowstone caldera, 640,000 years ago, 240 cubic miles
  • Santorini (not pictured), 5,500 years ago, 240 cubic miles
  • Yellowstone caldera, 2.1 million years ago, 600 cubic miles

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History Snippets: Santorini

“History Snippets” serializes small bits of research from an unfinished test project. The theme is technology and natural events that shaped our modern world.

Natural Disaster – Santorini

Santorini Island - NASA Satellite

Remains of Santorini Island after supervolcano of 3,500 BC. Scientists believe this would be one of the largest volcanic explosions to ever occur on the planet.

Santorini, a truly epic historical natural disaster, is getting a lot of play in current “catastrophe” speculation about how the world as we know it might end. The Mediterranean world, as Bronze Age Greeks would have known it, nearly did end.

A volcano in the “supervolcano” category is generally defined as one ejecting material in excess of 240 cubic miles (about 6x6x6 miles). In contrast, Mt. St. Helens ejected 0.24 cubic mile of material. The three islands were originally one large island; the enclosed “bay” is the massive collapsed volcanic crater or “caldera”, measuring about 4×8 miles — meaning, you could almost fit the entire Mt. St. Helens, crater and all, inside the Santorini crater.

The central island (blue, in this satellite photo) is actually the projecting central cone of the crater. The oceanic volcanic crater is the 4×8 mile bay itself. The tsunami (tidal wave) from the Santorini explosion is almost certain to have been responsible for the sudden destruction of  the Minoan civilization on the island of Crete, and to have decimated the early Greek tribes, on shorelines some 200km away,  to a fraction of their previous size.

The myths of the lost continent of Atlantis, and of Zeus’s mighty battle with the Titans, are conjectured to have originated in pre-history with the Santorini event. The Minoan civilization was destroyed at about that time. Known to ancient Greeks as Kalliste, Strongyle or Thera, this Aegean island group is today a beautiful and popular tourist port.

This is what is left of the island the Romans named “Santorini”. Athenians knew the island as Kalliste (“the most beautiful one”), Strongyle (“the circular one”), or Thera. Three distinct islands now, it was originally one single island.

This aerial (satellite) photo shows the circular volcanic crater or caldera, about 9×12 kilometers in size. Occurring as this event did in about 3,500BC, there is no recorded history of the event. Greek mythology is thought to have connected it with the battles of Zeus for dominance over the Titans.

Santorini is on the short list of sites mentioned in the persistent search for the legendary “lost continent of Atlantis”. Like Chicxulub crater and some of the other truly global scale meteor-strike sites, the actual scale of calderas like Santorini did not necessarily become obvious before the advent of aerial and satellite mapping.

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