72 votes
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Is the sea level rise unusual?

The problem is the increase in the rate of sea level rise. I pulled out some approximate numbers from the figure you presented: Can you see now how the sea level is rising much faster today than a ...
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35 votes
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Why is relative sea-level falling in Hudson Bay?

The area is experiencing post-glacial isostatic rebound. Much of Canada was covered in an extensive ice sheet in the last glacial period (the 'Ice Age'), from about 110 ka until 12 ka. The ice in the ...
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  • 10.8k
33 votes
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How much will sea level rise if all the polar ice melts?

Using the latest numbers from the 2013 IPCC report (Ch. 4, the Cryosphere), Antarctica contains 58.3 m of sea level equivalent (sle) and Greenland 7.36 m sle. Remaining glaciers provide an additional ...
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26 votes
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How can the world's sea level rise and fall simultaneously?

There are lots of controls on sea level, not just the volume of water in the world ocean. These controls operate on different time and spatial scales, and interact in nonlinear ways. As a result, both ...
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  • 10.8k
26 votes
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"Five of the Solomon Islands disappeared" due to sea level rise, how is this possible so quickly?

The sea is not the only thing that rises, the sea floor can also rise and fall in accordance with the underlying geology. Oceanic tectonic plates sink as they age (and thus get colder and denser), the ...
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  • 6,465
26 votes
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Why doesn't sea level show seasonality?

Sea level has a strong seasonal signal. The annual variability is less than the daily changes associated with tidal forcing in most locations, but still can be on the order of 5-10 cm (maximum values ...
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  • 14.7k
24 votes
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Are there secondary causes of sea level change?

Yes, there are lots of other factors. Factors affecting sea levels are no different from other natural processes: there is a large number of coupled, non-linear effects, operating on every time ...
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  • 10.8k
22 votes
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Is there a geological explanation for the recent Mammoth tusk discovery 185 miles off the California coast?

The mammoth probably died on land. Its remains got picked up by a glacier. The glacier carried the tusk down to the sea. Eventually, the ice containing the tusk broke off as an iceberg. The iceberg ...
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  • 3,028
20 votes
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What happens to sea level when a ship sinks?

It would go down. In order to float, an object must displace a volume of fluid that weighs the same as the boat. In the case of a ship, this volume is less than the gross volume of the boat, ...
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  • 10.8k
19 votes
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Are we experiencing lower level of gravity now compared to past?

Earth's radius is about 6400 kilometres. That's 6400000 metres. Let's say that you have a mound 20 metres high, burying an older settlement. Your new "radius" is now 6400020 metres. Let's say that $g ...
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  • 22.2k
18 votes

How much does sea level rise due to sediment deposition?

In a 1983 Journal of Geology paper by Milliman and Meade, "World-Wide Delivery of River Sediment to the Oceans" (link) it is estimated that the world's rivers carry about $13.5\times 10^9$ tonnes of ...
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  • 1,374
17 votes
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Potential explanations of Red Sea crossing

To my knowledge, the best study looking at potential explanations for the Red Sea crossing is the one by Nof and Paldor (1992). They present a couple of plausible scenarios for the crossing. The main ...
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16 votes

How much will sea level rise if all the polar ice melts?

As Peter Jansson explains, sea level rise purely due to melting of land-based global ice works out "to approximately 66.1 m sle." An issue with respect to sea-level rise that isn't often mentioned (...
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  • 2,826
16 votes

How long to melt all the polar ice?

The question is requesting an answer that has no practical application. So rather than improving on some hypothetical calculation, I will describe the problem and hopefully make the difficulty ...
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15 votes
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What influences tide-height the most? Can I guess the height by looking on a globe?

I don't know about the size of land masses, but their distribution and the shape of ocean basins definitely play a big role. When considering the ideal case of an all-ocean globe, i.e. one with no ...
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14 votes
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Effect on sea level if the Earth stopped rotating

Let's assume that the earth didn't suddenly stop spinning (because intertia and conservation of angular momentum would do all sorts of "interesting" things that are deserving of a What-If answer), and ...
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14 votes

Why is relative sea-level falling in Hudson Bay?

Because of post glacial rebound. The asthenosphere was pressed down under Laurentide ice sheet during last ice age and is now finding a new balance, without the weight of the ice. Note that around ...
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  • 5,896
14 votes

Sea Level Rise due to Climate Change

The first part of the association is that increasing levels of greenhouse gases in the atmosphere will cause rising temperatures on earth. Here is some information on why that is so, if you are ...
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  • 3,294
14 votes

Is the sea level rise unusual?

The problem is that sea level is increasing faster than ever in last couple thousand years. It is currently rising at 3.2 mm/year according to satellite data: The curve you showed is not a straight ...
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  • 373
13 votes
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Where does the biggest land-based ice cap reside?

Antarctica is the ice sheet (cap) that will contribute most IF it would melt completely. The 2013 IPCC report (Ch. 4, the Cryosphere) provides an estimate of 58.3 m of sea level equivalent (sle). ...
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13 votes

Are the oceans rising or the continents going down? How can we know?

To the best of our knowledge, sea-level is rising because the volume of water is increasing. There is substantial local variation in sea-level change; it's falling in some parts of Canada. But of the ...
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12 votes

Would it be geographically feasible to store water on land to counteract sea level rise?

Using the eTopo1 data Eakins and Sharman has calculated a hypsographic curve for the earth. In the elevation span between + 6 to -6 m they found that land area will change by 396 000 km2 per meter sea ...
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12 votes
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Will increased precipitation in Antarctica prevent sea level rise?

There is some scope for continuing debate because quantifying the various components of the ice/snow/water balance are fraught with difficulty, and many of the estimates have error bounds which ...
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12 votes

Is the sea level rise unusual?

Sea level rise from thermal expansion is a very slow process: oceans are 3.7 km deep on average, and water has a very large specific heat capacity. Here's a related diagram from the IPCC Third ...
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11 votes
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Sea Level in Paleogeographic Maps

There are various plate tectonic models around, that are able to provide insight in paleobathymetry and -altimetry. These models include information on sea floor spreading and subduction, which ...
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  • 2,602
11 votes

How much will sea level rise if all the polar ice melts?

(I can't comment on @kaberett answer as a guest) Don't forget the odd effect that as ice melts and the water warms from 0C to 4C, that water will contract slightly, dropping sea level a bit (at least,...
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11 votes

Water levels: What does "mBf" mean?

It is "mean sea level above the Baltic Sea", in meters (source on page 109). That explains why it is used mainly in East-European countries. Martin Ekman - The Changing Level of the Baltic Sea ...
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  • 2,625
10 votes

Historically, how has the fraction of Earth covered by water changed?

Can't say much about the later epochs, but the 'hellish Hadean' epoch without oceans is kind of an outdated idea. We have zircon records indicating that crust and oceanic formation was already done to ...
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10 votes

How long to melt all the polar ice?

Don't rest so easy, ravenspoint. The Laurentide ice sheet at its maximum extent was larger than the Antarctic ice sheet is now. The bulk of that ice sheet melted in two pulses of 2000 years each, ...
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10 votes

What is the appropriate vertical datum to use globally?

In a recent study, Talone et al. (2014) compare 4 different geoids and evaluate their effects for oceanographic studies. The four geoids they used are: EGM96: The Earth Geopotential Model 1996 ...
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