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50 votes
Accepted

What is the line crossing the Pacific Ocean that is shown on maps?

It's the international date line and marks the boundary between the time zones that are +12 and -12 hours from UTC / Greenwich. It should follow the +/-180 degree meridian line, but zigs and zags to ...
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42 votes
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Where on Earth is the magnetic field intensity stronger?

If we consider only the magnetic field generated by natural sources, and not the ones generated by human activities. The general trend is that higher intensities of the magnetic field happen close to ...
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39 votes

What is the line crossing the Pacific Ocean that is shown on maps?

Mkennedy's answer is right at identifying that line as the international date line and explaining how it works. However, I'd like to add on the main weird points of the line. North to south: In the ...
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22 votes
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Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

Absolutely not. First of all, "rare earth magnet ore", meaning the ores of metals like neodymium (Nd) and samarium (Sm), is not magnetic at all. It only becomes a magnet once you make a ...
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15 votes
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Are there seamounts as close as 100 m to the water surface and not inside any Exclusive Economic Zone?

Yes, there are many. According to the seafloor topographic data of ETOPO (1 arc second resolution), and the Exclusive Economic Zones (EEZ) database of marineregions.org. There are at least 157 ...
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13 votes

Where on Earth is the magnetic field intensity stronger?

Since it is not specified in the question (and to complement the other answer), the strongest magnetic fields on Earth are not naturally generated, but artificially. The current world record holder ...
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13 votes

Are there seamounts as close as 100 m to the water surface and not inside any Exclusive Economic Zone?

Checking the Wikipedia page on underwater volcanoes and listing them by height, I think the best candidate is Vema Seamount. Vema Seamount is in international waters and its shallowest point is at 11 ...
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12 votes

Is there a map that displays every country at its correct relative size?

Yes. Every equal-area map displays all countries (and other areas) in their correct relative size. Inevitably, they don't show the correct shape (unless you're looking at a globe). Personally, my ...
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12 votes
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Standardized scale for coastline length or mapping in general?

One standard that has be used by the USA is to measure the distant between points on the coast at intervals of 30 latitude minutes, as measured on a 1:1,200,000 scale map. See chapter 5 of ...
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12 votes
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Where on Earth has the least changing temperature?

To answer the first question, yes, there are maps showing the seasonal temperature variation, for example here Unsurprisingly, the equatorial areas have the least variation because the angle of the ...
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11 votes

Can living where (rare) earth magnetic ore is abundant provide any protection from cosmic radiation?

No. Cosmic radiation are high-energy particles that create particle showers high up in the terrestrial atmosphere. Those particle shower are heavily beamed downwards, and although in principle some ...
10 votes
Accepted

What is the chasm in the Arctic on Google satellite map?

You probably realise this, but you're not seeing that directly from satellite photos. Google Earth (or the "satellite" view in Google Maps) shows direct imagery on land, but underwater it shows a ...
9 votes
Accepted

At what depth does the underground begin to warm up?

Your question has an incorrect assumption built in. Near surface ground water temperatures are not generally colder, but rather reflect the average annual temperature. This will be colder than ...
8 votes
Accepted

How much of Earth's land area has antipodal land area?

A rough idea, using the Lambert Conformal image at the Cartopy projection list and Gimp: The gold area should be the overlap. So basically parts of South America with Indonesia and SE Asia... and ...
8 votes

Where to find an accurate Mercator Projection world image?

You can use Generic Mapping Tools (GMT): http://gmt.soest.hawaii.edu/ It's a command line tool for (among other things) plotting maps and geographical data. Works best on Linux/Mac but also on Windows....
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8 votes

A circle shape in Madagascar

It is an extinct volcanic crater. The location is not listed as one of the active volcanoes in Madagascar. Simplified geologic map of Madagascar (reference) shows the crater to be mapped as basaltic /...
8 votes

What is the average color of soil?

Soil color is largely determined by it's composition. There are three main components in soil: Gravel, sand, and silt. In essence, the type of stuff you find in sedimentary rocks. Usually, this is ...
7 votes
Accepted

Street and road data

Google Maps and MapQuest have gathered data and information through subcontractors and their own internal efforts. Their information is proprietary and is very hard to gain access to (and most methods ...
7 votes
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Old topographic maps of Odisha, India

The PCL Map Collection (University of Texas at Austin) is a huge online collection of maps. For India, they have a series from the U.S. Army Map Service which might be of interest, as it dates from ...
7 votes
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Geotiff for Elevation Data or NetCDF

'Better' will depend on your planned usage - any global product will have limitations in terms of overall accuracy and precision, and both the Aster photogrammetric data and the widely used radar SRTM ...
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6 votes
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How to Interpret this set of Latitude and Longitude?

It looks like your coordinates are written in decimal degrees but with the decimal points omitted. 34.144442 -118.654084 corresponds to 34°08'40.0"N 118°39'14.7"W. Google maps shows this to be a ...
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6 votes
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What are the best maps, if any, we have of the convection cells in the Earth's mantle?

If you're looking for a cool, well detailed map of convection cells that looks like a modern weather map....forget it. What you're looking for has been notoriously difficult to produce, if not ...
6 votes

Inconsistency between topographic survey and Google Earth

It's almost certainly a difference in the UTM zones. In most zones, the minimum easting value is 160,000 mE and the max is 834,000 mE (at the equator). People sometimes use the 'wrong' zone (i.e. not ...
  • 10.8k
6 votes

Is there a map that displays every country at its correct relative size?

This is pretty straight forward. The traditional map is very good for longitude and latitude. It's pretty lousy for the shapes and sizes of the continents cause everything close to the poles is ...
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6 votes
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Interpreting a geological map

1. What is the youngest/oldest rock in the geological history of this map. Your approach is the right one but isn't the limestone underlain by something? Drawing the AB cross section would be of ...
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6 votes
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In Geology - True Dip versus Apparent Dip: When dip is estimated along a line of section, how is that dip determined in relation to true dip?

This is an excellent question. The answer requires that one visualize a 3-dimensional space with a dip plane, a vertical plane coincident with, and aligned along, our line of interest, and the trace ...
5 votes
Accepted

What are these radial line patterns shown in representations of antarctica?

I can't be sure, but I strongly suspect that the radial lines in the first two images are the result of a bug in the software used to draw the map, probably resulting from vector polygons that are ...
5 votes

Topographic Maps

Map elements and signatures Every signature used in the map (except of elevation contour lines) has to be explained in the legend. For example, the dashed line is not explained. Your map needs a ...
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