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0Erinome:Hello dear friends, welcome to our podcast! Today, Enceladus and I are going to talk about a cool topic—why sea water doesn't freeze easily. Have you ever thought about that, Enceladus?
Enceladus:Um, yeah! Like in winter, lakes and rivers on land freeze, but the sea often stays unfrozen. Why is that?
Erinome:Let’s start with the basics first. Do you know what "sea ice" is?
Enceladus:Is it just ice from the sea?
Erinome:Kind of! Sea ice is mainly saltwater ice formed when seawater freezes directly. Oh, and in a broad sense, it also includes river ice and icebergs in the ocean. Cool, right?
Enceladus:Wow! So there are different types of sea ice?
Erinome:Yes! Two main types: fixed ice and drift ice. Fixed ice is frozen to coasts, islands, or the seabed—it moves up and down with the sea level. Drift ice floats on the surface and moves with wind and ocean currents.
Enceladus:Drift ice sounds dangerous for ships, maybe?
Erinome:You’re right! The news said drift ice can affect ships and harm海上 buildings. But let’s get back—why is sea water hard to freeze?
Enceladus:Is it because of salt? I remember fresh water freezes at 0℃.
Erinome:Bingo! Sea water has a lot of salt. The average salt content is about 34.48‰. So its freezing point is lower than fresh water.
Enceladus:How much lower?
Erinome:Around -1.9℃! So even if the temperature is 0℃, sea water won’t freeze. It needs to be much colder.
Enceladus:Oh! That’s a big difference. So salt makes the freezing point drop?
Erinome:Exactly! And there’s another reason: sea water is always moving. Wind, temperature differences, and density make it flow, so ice can’t form easily.
Enceladus:Like, the water keeps moving, so the cold can’t make it freeze quickly?
Erinome:Yes! Unlike a still pond, the sea is always "dancing"—hard to freeze. But here’s some sad news: sea ice is getting less because of global warming.
Enceladus:Oh no! Really?
Erinome:Yeah. From 1981 to 2010, Arctic sea ice area decreased at least 13.1% every 10 years. That’s a lot!
Enceladus:What about Antarctica?
Erinome:Even worse. From 2014 to 2017, Antarctica lost over 2 million square kilometers of sea ice—bigger than Mexico! And it’s melting faster than the Arctic.
Enceladus:That’s so sad… Why does this matter?
Erinome:Sea ice is important! It reflects 50% to 70% of sunlight back to space, keeping Earth cool. But when it melts, the water absorbs heat instead.
Enceladus:Oh! So more melting means more heat, which makes more ice melt? A bad cycle?
Erinome:Exactly! And it hurts animals. Polar bears in the Arctic lose their ice homes, penguins in Antarctica too. Also birds, whales, seals… the whole food chain is in danger.
Enceladus:Wow, that’s serious. What can we do to help?
Erinome:Small things! Save water and electricity—turn off lights when leaving a room, don’t waste water. Green出行 like walking or biking instead of driving.
Enceladus:Oh, and don’t litter! And use fewer disposable things, like一次性筷子.
Erinome:Yes! Every little action helps slow global warming and protect sea ice.
Enceladus:I never thought sea ice was so important. Now I know why we need to care.
Erinome:Me too! It’s not just ice—it’s home for many creatures and keeps our planet balanced.
Enceladus:So remember, friends: save energy, reduce waste, and protect our sea ice.
Erinome:Okay, that's it for today. Let's all do our part to keep the sea and its ice safe. See you next time! Bye!
Enceladus:Bye!
