There are about 200,000 glaciers in the world, covering 726,000 km2 with an average thickness of several hundred meters. In the process of global warming, the glaciers are slowly melting. Estimate the rise of the average sea levels in case they are all melted. Assume the radius of the Earth equals 6400 km.
pls help I got answer but for some reason its minus. Thx :)
yeah? How did you get a minus value?
Figure the volume of the glaciers.
The rise in sea level is that volume, divided by the surface area of the earth
Not strictly true, since not all of the surface is covered by oceans. But, as the sea level rises, the area of water increases, making it rise more slowly. Since they don't tell you the percentage of earth's surface that is covered by water, I guess you are to assume the whole area of the earth.
Yes, close enough, particularly considering the likely result.
To estimate the rise in average sea levels in case all the glaciers in the world are melted, we need to consider the volume of water that would be released from the glaciers and how it would distribute over the Earth's surface.
Let's start by calculating the total volume of ice in the glaciers. The formula for calculating the volume of a cylinder, such as a glacier, is V = πr^2h, where 'r' is the radius of the glacier (we'll assume it to be 1 km, or 1000 meters), and 'h' is the average thickness of the glaciers (several hundred meters, let's assume 300 meters or 0.3 km).
Using the given information:
- Number of glaciers: 200,000
- Area covered by glaciers: 726,000 km^2
- Average thickness: 0.3 km
We can calculate the total volume of ice in the glaciers:
Volume = πr^2h = π(1000)^2(0.3) = 300,000π km^3
Next, we need to determine how much sea levels would rise if this volume of ice were to melt and distribute evenly over the entire surface of the Earth's oceans.
To estimate the rise in sea levels, we can divide the total volume of ice by the total surface area of the Earth's oceans, assuming a radius of 6400 km. The formula for calculating the volume of a sphere is V = 4/3πr^3.
Surface Area = 4πr^2 = 4π(6400)^2 km^2 = 515,379,520π km^2
Rise in Sea Levels = Volume / Surface Area = (300,000π) km^3 / (515,379,520π) km^2
Canceling out the π, we get:
Rise in Sea Levels = 300,000 km^3 / 515,379,520 km^2
Calculating this value:
Rise in Sea Levels ≈ 0.582 km
Therefore, if all the glaciers in the world were to melt, and the resulting water were to distribute evenly over the Earth's oceans, the average rise in sea levels would be approximately 0.582 km or 582 meters.
Note: It's important to consider that this calculation assumes a simplified scenario where the meltwater is perfectly distributed across all the oceans. In reality, factors such as regional variations in sea level rise and land rebound due to the removal of the weight of glaciers would affect the actual rise in sea levels in different locations.