Sunday, November 1, 2015

The Oceans!!! They're Rising!!! - Day After Tomorrow Post

Over the last 18 years alone, according to NASA, the average height of the worlds oceans has risen over 65 mm. Now, that may not sound like much, given its the equivalent of about 6 and a half centimeters, but one must think about just how much space the ocean covers on Earth. There is 2.25 x 1011 square meters that the SURFACE of our ocean covers. Adding a 6.5 centimeters or .065 meter depth to that would calculate to 1.46 x 1010 cubic meters of water. Enough to fill every swimming pool on earth, 13 times. Below is a graph of the water level over the last twenty years.

This 6.5 centimeters, while relatively small now, is continuing to grow at an increasing rate, as the ice covering Antarctica and Greenland is being melted away by a higher global temperature. All this ice runs into the ocean, increasing the total volume of water in our oceans. Another significant factor in rising sea level is Thermal Expansion. The same heat that is melting the ice caps, is also heating the mean temperature of the ocean. This causes the individual molecules of water to move more vigorously, thus taking up more space. The video below better explains the combination of the two phenomena and their impacts of sea levels.

As far as the movie, The Day After Tomorrow, is concerned, while the basic premises of thermodynamics are correct and the movie does a good job of explaining the science, the time it takes for the entire process to happen in the movie is way too quick. Even if some idiot scientist cracked half of a glacier and caused it into the sea, the effects of such an event would speed up the process, but not enough for a global winter in 15 days.

1 comment:

  1. I like how you focused on one particular aspect of global warming. It allows you to be more persuasive and go deeper into explaining/arguing that topic. Good visuals, too. I hadn't seen the plot of ocean level rise before -- pretty scary for us in Charleston!