# Tag Info

19

I think you are too into the numbers. When talking about longitude and latitude they are two different things. Longitude goes east and west from a point on the earth from 0 to 180 degrees east and 0 to 180 degrees west and describe semicircles of equal length running from the north pole to the south pole. Latitude however is in degrees north or south of ...

16

I don't understand the last sentence about decimal places, but I can tell you about the relationship between lat, long and distance. Over two centuries ago, the meter was defined as one ten-millionth (1/10 000 000) of the length of a quadrant along the Earth's meridian; that is, the distance from the Equator to the North Pole. So, for latitude the number of ...

15

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 seafloor features higher than -100 m (closer than 100 m to the sea surface). With that data, I made the following figure that shows: ETOPO topographic data All EEZ ...

13

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 meters from the surface. It is so shallow that it represents a navigation hazard.

12

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 favourite projections are pseudocylidrical equal-area projections, such as: Equal Earth projection Mollweide projection Eckert IV projection Tobler ...

8

Latitudes are "parallels" while longitudes are "meridians" that all meet at the poles. For latitude, there is a set distance traveled per degree latitude no matter where you are on a spherical globe. For longitude, it depends what latitude you are at. (source: learner.org) .......................... .............. Image source: https:...

8

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 Antarctica with the far northern islands of the northern hemisphere, plus a few smaller areas from islands like New Zealand and Hawaii and even smaller. That ...

7

To answer the question in the title (with another question): better for what? To answer the questions in the body: there is another system called rectilinear or x-y-z Cartesian coordinates. This system is the same as the 3-d Cartesian coordinates you used in calculus class. The center of the Earth is (0,0,0), and generally the z-direction goes to the poles, ...

6

There are many reasons. First, measuring from sea level is traditional. It started before we had an accurate way of measuring distance from the center of the Earth, and probably before most people knew it was (approximately) a sphere. But anyone living by the shore could determine sea level to within a few feet. Another reason is that measuring from sea ...

6

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 the zone that the location is actually in) if it's more convenient to use a neighbouring zone for some reason. For instance, maybe I have coordinates for 100 ...

6

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 expanded. A more accurate map has to look like a carved up sphere on a flat sheet of paper. This one claims to be the most accurate: http://imgur.com/gallery/...

6

Most of our geographic and astronomic terms were developed in pre-history in the northern hemisphere. Even early astronomers noticed that Polaris, the north star, was 'up' in the night sky, so north as 'up' simply became the convention.

6

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 the 50's and has a decent scale (1:250,000). They also have older maps from the British era, but the series doesn't seem to be complete. It might be worth looking ...

5

There is no good reason. It's simply a convention that someone started a long time ago and that stuck. Like the question whether an hour is divided into 60 minutes and a minute into 60 seconds. If you go to Australia, you will find plenty of maps for tourists that show Australia at the top and Europe at the bottom.

5

There is a site that will show you the antipode for any location, and takes you through the calculation if you need it - https://www.geodatos.net/en/antipodes/united-states/monterey. Looking at the question, and your own potential answer, that you originally posted on the GIS SE, you correctly calculated the longitude of the antipode, but you mistakenly ...

4

Your understanding is inaccurate. The shifts by $\frac{1^\circ}{24}$ are only relevant for figuring out, where the pixel centers are located and where to start when you are looking to find the right grid index for a certain point. As for the resolution, it is much simpler. We have $4320$ pixels covering $360^\circ$ in longitude direction, i.e. a resolution ...

3

The UTM coordinate system, is a kind of Transverse Mercator projection separated in longitude bands and restricted in latitud extent such that the distortions associated with the projection remain small. Also, the UTM coordinate system is conformal projection. Therefore, it preserves the angles. That means that within the UTM zones, a straight line in UTM ...

3

First step - draw a strike line where line A intersects the 400 m line. Second step - you know that the sandstone layer is of equal thickness and dip, so you can draw a parallel line at the place with line B intersects the 400 m line. This will give you the thickness, as expressed on a horizontal surface. You know what the dip angle is, so getting the real ...

3

The other answers are correct on the subjectivity of "better." They are also right, in that the answer you may get will depend on your application. My answer is yes and no. Yes: There is a way to convert from latitude-longitude coordinates, but it depends on the projections. Python has become my favorite tool for programming and creating plots, especially ...

3

Better is first and foremost opinion based so cannot be answered with a conical answer, but, will give it a stab anyway. First, it is entirely dependent on application. Start with your suggestion of a 0,0 based coordinate system. This is used for many maps. It also has very little to associate it with reality as it is a two dimensional representation for ...

3

You are correct about the maximum value, you just have the easting and northing backwards. In your first example, the easting is 414668 m and the northing is 6812844 m. The convention is eastings first. You can think of UTM coordinates as $(x, y)$ pairs, and they are sometimes labelled as such. Here's the conversion offered by one converter: As you say, ...

3

As far as I know there are no official data on this. All I can do is give a rough estimate, based upon work and personal interest in about 30 countries, over 40 years. We can say with certainty that everywhere has been mapped at the 1: million scale although, at this 'reconnaissance scale', at least half of the land surface is only sketchily known, with ...

3

Count data. Quantitative data that varies discretely and arbitrarily along some scale can be called count data. Nick Chrisman (1995; Beyond Stevens: A revised approach to measurement for geographic information, presented at Auto-Carto; see this PDF for a transcript) pointed out that there are many more typologies of measurement than the 'classic' four ...

3

Found in https://twitter.com/amazingmap I can't personally vouch for accuracy. From tweet, several complaints about Antarctica, "wrong pole", etc. New favourite map projection. Hellereal Boreal Triaxial Projection From tweet World Mercator map projection with true country size and shape added #Map #Maps #Amazingmap #Amazingmaps #Mercator

3

It all depends on exactly what you mean by "halfway around the earth heading due north or south." One theoretical interpretation of that phrase is that, starting in Monterey, California, you start heading south, and you continue walking south until the distance that you've walked south is half the circumference of the earth. (Throughout this answer,...

3

You can travel in north-south direction to go around the world... but you can also travel east-west. Going around the equator halfway will see no north-south change, but still be halfway around the world... so that should make clear that two antipodal points can be much less north-south change than between the North Pole to the South Pole. They can even ...

2

Surveying is the process of taking topographical measurements of latitude, longitude and elevation. It is also the process of marking out lines for engineering/construction designs of such things as roads, tunnels, fence lines, boundaries & foundations of buildings. Surveying provides the topographical data that cartographers, engineers and other ...

2

I don't think there are any general books on graphic design for geologists. However, there are some books about graphical standards for geological maps and sections: FGDC Digital Cartographic Standard for Geologic Map Symbolization British Geological Survey Standard Cartographic Index [PDF] Australian Bureau of Mineral Resources symbols guide [PDF] Shell's ...

2

There is an very detailed "Digital Cartographic Standard for Geologic Map Symbolization" by the Federal Geographic Data Committee (FGDC) including e.g. color and pattern charts. Check the main website for the latest version of the Standard, availabe in PostScript format, as pdf, or as ArcGIS10 template.

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