Most Popular
1500 questions
31
votes
2 answers
Is this XKCD comic an accurate timeline of the earth's average temperature?
Apologies for the length of the image, which I found at http://xkcd.com/1732/.
I'm mostly interested in the temperature line itself, both the historical data and the forward projections.
The reason I ask is that I'd like to (in a classroom context)…
user1205901 - Слава Україні
- 535
- 4
- 9
31
votes
4 answers
Why is Earth's outer-core liquid?
The Earth's inner core is solid because despite the enormous temperature in this region, there is also enormous pressure there, which in turn raises the melting point of iron and nickel to a value above the Earth's core temperature.
Now as we move…
Kenshin
- 7,576
- 12
- 42
- 81
31
votes
5 answers
Is it possible for rivers to freeze completely and stop flowing?
Is it possible for rivers to freeze completely in the winter and stop flowing? Are there known examples of this? If yes, how large can these rivers be and where does the water go?
There are several large Siberian rivers that empty into the Arctic…
Glacialis
- 682
- 1
- 5
- 10
31
votes
2 answers
Why are there no hurricanes in the southern Atlantic basin?
We see tropical cyclones (going by different names e.g. hurricane, typhoon, cyclone) all over the tropics, but it seems that there are never any storms in the southern Atlantic. See this map of tropical cyclone activity and note the lack of…
Richard
- 2,758
- 2
- 17
- 35
30
votes
6 answers
How much will sea level rise if all the polar ice melts?
There are many movies about global warming, which say that melting of all polar ice would cause the whole world to suffer a huge flood. According my research (teachers, TV, Internet) people hold one of these two viewpoints:
There will be a huge…
Poomrokc The 3years
- 1,171
- 3
- 11
- 18
30
votes
1 answer
What is the status of the Raymo & Ruddiman idea that Tibet cooled the Earth?
What is the current status of the Raymo & Ruddiman hypothesis that the uplift of the Tibetan Plateau during the Cenozoic cooled the Earth, resulting the current ice age(*)?
cf. Raymo, M.E. and W.F. Ruddiman (1992) Tectonic forcing of late Cenozoic…
winwaed
- 3,893
- 17
- 38
30
votes
3 answers
Why is Earth's inner core made of an iron-nickel alloy?
This question has puzzled me for a while. I know that earth's mantle is made of different minerals, metals and rocks etc. and that has always made complete sense to me. But why is the inner core made of an iron-nickel alloy? The only reasons that…
tux
- 1,672
- 4
- 17
- 25
30
votes
2 answers
At what humidity does it start to rain?
As far as I understand it is perfectly valid for air to have 100% humidity. At that point, all water can still exist in form of vapor, non-condensed.
Does it immediately start to rain if humidity is >100%?
If so, why do we have slight rain and…
Thomas Weller
- 403
- 1
- 4
- 10
30
votes
3 answers
How would an icicle "grow" upwards?
The other day a friend of my dad's showed him a picture of an icicle that appeared to be "growing" upwards out of a crack in a sidewalk. There were no roofs, overhangs or vehicles parked near by... It looked like a stalagmite you would see in a…
L.B.
- 684
- 5
- 22
30
votes
4 answers
Can pyroclastic flows cross water?
While reading the Wikipedia article on pyroclastic flows, I noticed that there's a section called 'Interaction with water'. This piqued my interest, as I was under the impression that lava generally doesn't interact much with water other than…
user13
30
votes
3 answers
Equinoxes and solstices: start of the season or mid-season?
In the United States, the upcoming autumnal equinox is marked on most calendars as the "first day of autumn." Similarly the solstices are commonly called the "first day of summer" and "first day of winter." However in most other languages -- and…
rob
- 451
- 4
- 13
30
votes
6 answers
Why aren't weather balloons left in the atmosphere permanently?
I was reading about weather balloons and the articles said that weather balloon flights usually last about two hours. When I looked up why, some articles said that when the balloons get high enough in the atmosphere, the balloons pop from the low…
user11937382
- 595
- 5
- 7
30
votes
2 answers
Where on Earth is the magnetic field intensity stronger?
Are there places on Earth that have a strong magnetic field other than the magnetic north and south poles?
Can living where (rare) earth magnetic ore is abundant provide a mini-magnetoshere?
Muze
- 1
- 4
- 17
- 53
29
votes
3 answers
Why are hail storms always brief?
It can rain all day, and it can snow for hours on end, but hail always seems to fall for short periods only. Why don't you get prolonged periods of hail?
Jack Aidley
- 393
- 3
- 7
29
votes
4 answers
Why is relative sea-level falling in Hudson Bay?
Why is the sea level in Hudson Bay decreasing so much? Hudson Bay is pretty far up north, much closer to glaciers. Would it make sense for it to recede at this level with sources of fresh water relatively close?
Lucian09474
- 1,942
- 2
- 17
- 25