Saturday, May 22, 2010
Wednesday, May 19, 2010
The Mount St. Helens volcanic eruption is the most famous volcanic eruptions in US history. The eruption and ensuing pyroclastic flow killed 57 people and dropped the elevation of the summit more than 1300 feet. The amount of ash debris was almost 1 cubic mile in volume. Imagine a box a mile on each side? That's alot of material. A look at Mount St. Helens before the eruptions.
What about the phrase "pyroclastic flow". What does this mean? It is term describing the flow of hot gas and collective material from the volcano that flows down the side of the mountain. It can reach speeds of 450 miles per hour and temperatures of close to 2000 degrees and has been know to cross bodies of water for miles. Its these pyroclastic flows that cause the majority of the damage in volcanic eruptions. A look a year after the eruption. Notice the crater in the middle.
A satellite timelapse over the last 30 years showing the evolution of the mountain since the eruption.
Tuesday, May 18, 2010
image credit: "uscgd8" at flickr
The Loop Current has been making the news since the Gulf Oil Spill occurred a few weeks ago.
Now that the Oil Spill is drifting east, the Loop Current is now playing a pivotal role in where the oil spill travels.
What is this The Loop Current? is an ocean current that resides between the Yucatan Peninsula and Cuba. It originates in the Caribbean Sea, flows out into the Gulf of Mexico and loops around southeastward into the Florida Keys and into the Bahamas. Its a few hundred miles wide and runs more than a 1000 feet deep.
According to the Cooperative Institute for Marine and atmospheric studies, the Loop Current draws its waters from the Yucatan Current, which is ultimately fed by the Caribbean Current, Guiana Current and North Equatorial Current. This provides a vital link between North Atlantic and South Atlantic waters. Here is a graphic showing the ocean currents around the planet from the 1940s. The animation below shows the currents in action.
Althought this might be the first time you've heard about the Loop Current, you don't have to go far back in
history to find that the Loop Current was involved in another natural disaster. Remember Hurricane
Katrina? The Loop Current was directly responsible for its rapid intensification into the historic Category 5
hurricane we all remember. Notice how the track of Katrina and Rita coincides with the Loop Current.
Back to the oil spill. This same Loop Current that played a direct role in Hurricane Katrina's development
is directly involved with the track of the oil in the next severe weeks.
How can we accurately forecast the movement of the oil spill? For years, the National Oceanic and
Atmospheric Administration has been doing research on the ocean and its movement. NOAA launches surface buoys to gain valuable data on the oceans and their behavior. Here is the track of ALL of the buoys from 1978 to 2003.
You can see how the current behave near the loop current and how the current ntersects with the Gulf Stream around Florida and up the eastcoast. Expect the Loop Current to strengthen hurricanes this season. More on that later this summer.