Saturday, June 27, 2009

Ask the Experts: Could there be another Ice Age someday?

There have been many ice ages throughout the history of Earth, and not only the ones when mammoths and saber tooth cats lived. Ice covered much of the planet before dinosaurs evolved over 250 million years ago. There was also another ice age almost 700 million years ago, during a period called the Precambrian, when all that was around was soft-bodied animals like jellyfish and worms in the oceans.

Scientists can tell there was ice because we find rocks from those times that have marks from being scraped or moved by glaciers - huge frozen rivers of ice flowing slowly down mountainsides. Some of these rocks were found in areas that, at the time, were in mid latitudes or even the tropics - imagine ice and blizzards in the Caribbean!

There are many things that can push Earth towards an ice age, and when several of them occur together, it can shift the environment far enough to cause glaciation (the process of covering Earth with ice) to begin. The sun has become hotter over time, greenhouse gases increase and decrease, the orbit and tilt of Earth fluctuates, and the movements from plate tectonics and geological activity continue to change the planet we live in. All these environmental factors play a role in creating an ice age like the one our Mastodon, 'Max', lived in.

All these factors react with each other and themselves in a complex dance that determines the climate of Earth. For example, ice is white and reflects sunlight very efficiently. When ice begins to spread, more sunlight gets reflected away, which makes the Earth cooler, which causes the ice to spread even more. Once you get a feedback loop such as that going, it takes a lot to get it to completely stop, and that is how ice ages can begin.

About 12,000 years ago, the last glacial period ended and we entered a warmer interglacial period. Technically, we're still in an "ice age" - if there's ice covering large portions of the Earth, like it does in Antarctica or the North Pole, it's still considered an ice age - though right now we're in a relatively warm period where most of the ice has gone. That could change, though, if we enter a new glacial cycle. The geological record shows that's probably going to happen between 28,000 to 88,000 years from probably no need to go buy a heavy jacket and a snowmobile just yet.

DJ and DA

Friday, June 26, 2009


Our new exhibit, ART meets SCIENCE, has been open for a few weeks now and the response has been great! Its fantastic to see the creativity our visitors demonstrate - every week there's examples of new and innovative ideas on the exhibit floor. Its amazing that they can make such impressive structures from the simple KEVA blocks.

Our opening day competition was a great success, too. All the contestants' entries were impressive, but a few stood out as exemplary. You can see images of the winning designs here on our website.

Its also very fun to watch people of all ages enjoying the exhibit - from young schoolchildren on field trips, to parents and even grandparents. Some of the adults get even more into it than the children!

We have another competition coming up this weekend, as well as competitions in July and August - you can sign up on our webpage if you want to participate. It will be very interesting to see what kind of designs come out each month!