Thursday, March 10, 2011

Nyiragongo

As the map at right shows, Nyiragongo Volcano is located in Virunga National Park in the central African country Democratic Republic of the Congo (DRC).

Here's a trivia question... What's been the deadliest war in the world since the end of World War II?  Answer:  The Second Congo War from 1998-2003 (hostilities still occur) which resulted in an estimated 5.4 million deaths.  Now raise your hand if you've even heard of it.  As with most things occuring around the world, if Americans aren't involved, we don't give a shit.

The war was driven by tribal hostilities (partly, but not wholly due to how European colonial powers drew boundaries between various African countries) and the control of trillions of dollars of mineral wealth still in the ground (subject of  future post).  Tribalism and greed resulting in the killing of lots of powerless people - same old story repeated throughout human history.

Note those long, linear lakes on the eastern boundary of the DRC in the map above?  These are part of the western arm of the East African Rift system.  This is where Africa is trying to rift apart -- easternmost Africa is part of the Somalian subplate and it's pulling apart from the bulk of Africa (the Nubian subplate).

As rift valleys form due to tensile stresses in the continental lithosphere (crust plus the rigid part of the upper mantle), faulting occurs and sections of the crust drop down into a rift valley.  Sometimes these valleys fill with long, linear lakes.  Earthquakes frequently occur along these border faults and as the crust stretches, it also thins, allowing magma to reach the surface and form volcanoes.

The map at left show seismicty, earthquakes recorded over a few decades in Eastern Africa.  The size of the dot corresponds to the magnitude of the quake.

In January of 2002, Nyiragongo had a significant eruption which is summarized in the image below taken from a BBC News story published at the time.















Rivers of lava flowed down the flanks of the volcano, destroying 14 villages, damaging the airport, and passing through the city of Goma.  Some 300,000 -400,00 people fled to Rwanda and about 50 people died (mostly from carbon dioxide asphyxiation).  A large number of earthquakes were also associated with this eruption.
   

Here's Nyiragongo Volcano smoking away.  A direct result of deep Earth forces rifting apart the continent of Africa and a ticking time bomb.

The Big Picture by The Boston Globe has a great series of photographs of scientists and crazy adrenaline junkies descending into Nyiragongo Crater.  Go see it here:

     Nyiragongo Crater: Journey to the Center of the World

Rapelling down over 1,000 feet into the crater is incredibly risky.  Not only does one risk death from falling rocks and the highly unstable volcanic slopes with chemically-rotted volcanic rocks and frequent tremors, there is the risk of asphyxiation from carbon or sulfur dioxide, and the risk of even a small amount of lava "burping" out and spilling over the crater rim.

This is one of my favorite pictures from the set.


The Eye of Hell.  Below is a time-lapse video of the Nyiragongo lava lake from another source.  In this video, 1 second of video time is equal to 1 minute of real time.




This video makes me think of the earliest Earth, four and a half billion years ago, still mostly molten with a thin "scum" crust forming and reforming and moving around in a frenetic type of plate tectonics.  It seems like it would be a neat place to visit and see (which will never happen).

No comments:

Post a Comment