Why Is Old Sea Ice Less Salty than the Ocean It Came From?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why is old sea ice less salty than the ocean it came from?

The Big Idea

Old sea ice is less salty than the ocean it came from because the salt slowly drains out of it! Over time, the ice becomes much fresher. Let's follow the salt.

Salt Pushed Out

Step one: salt pushed out. When seawater freezes, most of the salt is pushed out of the ice crystals. It ends up in tiny pockets of very salty water called brine.

Brine Drains

Step two: brine drains. Over time, the brine slowly drains downward through the ice and back into the sea. This takes months and years.

Fresher Ice

Step three: fresher ice. Older ice has lost most of its brine, so it can be much fresher than young ice. Very old Arctic ice was once melted by explorers for drinking water.

A Closer Look

Let's take a closer look! The sea starts out salty. Salt gets trapped in tiny pockets inside new ice. Gravity pulls the salty brine downward. What is left behind is much fresher. That is how ice cleans itself.

Quick Facts

Quick facts! Young sea ice is quite salty. Old ice can be fresh enough to drink after it melts. Even so, never taste ice from the wild, because it may not be safe. Do tests like this with a grown-up. Salty water drains and leaves fresher ice behind.

Think Like a Scientist

Now, think like a scientist! With a grown-up, freeze a dish of salty water. Then let it start to thaw on a tilted tray. Watch the extra-salty liquid drain away from the ice. Do not taste it!

Outro

Old sea ice is fresher because salty brine drains away. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!