# Tag Info

15

I get 40.44% With a workflow using a tiny bit of Python. After Polygorial‘s comment I am adding (Feb 17, 2021 update) point zero to state more explicitly that this method requires a map like the one I used (Gall-Peters projection) with equal area projection, as regions of same area on the Earth’s surface will have the same area on the map, and therefore ...

13

From http://www.physicalgeography.net/fundamentals/8o.html and http://www.eoearth.org/view/article/154984/ The spatial distribution of ocean regions and continents is unevenly arranged across the Earth's surface. In the Northern Hemisphere, the ratio of land to ocean is about 1 to 1.5. The ratio of land to ocean in the Southern Hemisphere is 1 to 4. This ...

13

the trick is not all isolated rocks are produced the same ways. Of the two in your pictures the first is an old volcanic events; intrusions, dikes, ect. depending on which rock in the region you are talking about. The whole deccan plateau region is full of them, some have been exposed on the surface via erosion. Basically everything else eroded faster than ...

12

The short answer is that people do talk about it. It is commonly referred to as "land use change". In general, the carbon dioxide equivalent of the effects of land-use change is on the order of 10% of the total anthropogenic contribution to CO2 emissions. This may seem small, but it is important to realize that land-based plants are only a portion of the ...

12

I wrote a little Matlab script to estimate this approximatively. Here is the result: colour denotes the total land area inside the hemisphere centred on a particular surface point. The red point is the maximum. This gives me a maximum for the hemisphere centred on 1.7582°W longitude and 40.7692°N latitude, roughly in Guadalajara, Spain. If I calculated ...

11

It would be a strange coincidence (but of course possible) if the landmass would be exactly evenly divided between the northern and southern hemispheres, as defined by the equator. However, you can cut the globe with another plane and form two hemispheres that have the same landmass, eg. any vertical plane that goes through the Geographical centre of Earth. ...

11

For rain to fall, water vapour must exist in sufficient quantities in the atmosphere. The main source of atmospheric water vapour is evaporation from oceans. However, evaporation from large bodies of water such as lakes and dams also contributes. Another significant contributor, on a local level, is transpiration from forests. the Amazon alone creates 50-...

11

This is a large glacier calving event. Calving occur at the front of the glacier, probably a very wet (and likely warm based) glacier where a considerable amount of water is flowing out of the system (thus from the glacier to the sea). The amount of water is important as it can accelerate the ice flow speed on the valley floor, enabling the breaking of big ...

10

Leaves, mostly. Photosynthesis requires carbon dioxide, and it gets it via stomata - small controllable pores in the leaf. When the stomata open, water goes out, because the air is generally drier than the interior of the leaf. Water in the leaves is drawn up from the roots, via the xylem, using the suction from the lost water in the leaves, and also acting ...

10

The average ecological footprint of a US citizen has been estimated as 8.00 global ha. Multiplying 8.5 million by 8.00 hectare gives 680,000 km², or around 5 times the area of New York state. Of course, this calculation contains a lot of assumptions and simplifications. This doesn't mean you could simply allocate 680,000 km² around New York City and use ...

8

You would have to cut somewhere along this circle: The only landmass here is New Zealand, eastern Australia, eastern PNG, western North America and some Pacific islands. I'm pretty sure you can tweak it a bit, but that's the basic idea. Notice that this actually shows less than a half because of the relatively low altitude. If you "zoom out" infinitely you'...

7

This optical illusion is due to refraction of visible light due to density gradients near the surface and the fact that the index of refraction in a medium is dependent on the density of the medium. In an atmospheric density gradient light will bend toward the direction of increasing density. When it is cool at the ground and warms up with height this ...

6

The total land area of earth is approximately 29%. So, in order to have a hemisphere with more land than water, out of 29% of total land area we need to have at least 25% of it concentrated in that hemisphere. Now for the ease of understanding, what does 25/29 of total land area means? It approximates to 86% of the total continental surface area. Area of ...

6

This is probably more of an English language question than a science question. The answer to it depends on the extent of a person's vocabulary & knowledge of a particular field of engineering. Over a period of time, in the media I have read & heard mine "tunnels" incorrectly being called shafts. Mine shafts are vertical or near vertical. What most ...

5

Curved trees are a sure sign of movement of surface. Special geomorphic shapes are also present in a slowly developing landslide. At the top of the landslide cracks can start to show, at the foot you can find "bumps" in the soil. Water will have difficulties to drain at the foot of the landslide. Here are a few examples of literature that should be ...

5

City Green Space Within New York city, 14% of the city, 29,000 acres (11,735 ha) is parkland. Water Supply The Management of New York City Water Supply Lands document, by the New York City Department of Environmental Protection, states the surface water supply system yields 1.3 billion gallons (4.92 GL) of unfiltered drinking water each day to ...

5

Are there papers or datasets of average CO2 concentrations down at ground level (say 0-20 metres upwards from the ground), in the spaces between buildings - streets, parks and so on? Yes, THE URBAN CO2 DOME OF PHOENIX, ARIZONA has measurements at a height of 2 meters above ground level, 1.6 km horizontal resolution. CO2 concentrations are 555 ppm near ...

5

The approach used by Alton et al 2011 is appropriate for the scope and intent of this paper - to demonstrate a weakness in the approach - but is not a comprehensive analysis of PFTs in models. I think it is useful to question the use of PFTs but incorrect to conclude that Alton et al claim PFTs are not useful. Alton et al show that albedo, net shortwave ...

4

It depends what your practical purposes are. Maybe you can treat it as 0. But in general, no, because it is not closed, due to geothermal heat flux, and anthropogenic imbalances. Also, even if assuming 0, that would be over long time scales and integrated over the earth surface. There are spatial heterogeneities.

4

Dry down is mainly dependent on the speed where a local water storage would be depleted, considering those components extracted from the simplified water balance equation water input (precipitation) local drainage capacity (runoff, infiltration, percolation) evapotranspiration storage change and capacity (pores in the rock and soil) To generalize your ...

4

Provide a monthly average in every grid cell, and describe how many measurements were used for each cell. There is no fixed rule for the minimum number of days for reporting a monthly average. A reasonable threshold will depend on the geophysical quantity of interest y, in particular on how much y varies on short and long timescales. If y varies from ...

3

In the attached JPL graphic from Heflin et al, 2007.9- every data point located south of the equator shows a northward component of motion (except the Nazca plate west of South America and a small portion of the Eurasian plate in Indonesia). Australia, for example, is moving dramatically northeastward, compared to other regions. If landmass evacuation from ...

2

In a topological sense, if it's connected by an isthmus then it isn't an island. That doesn't mean that it might not be called that - but the answer is a cultural & political one, and hence won't adhere to strict definitions.

2

I think the naming difference is largely qualitative and even arbitrary in some cases. There are lots of 'islands' that are technically connected to a larger landmass by an isthmus of some sort, which would make them peninsulas technically, and not islands. If you take the definition of a peninsula to be a body of land surrounded by water on three sides, ...

2

The Northern Hemisphere is 40% land and 60% water. The Southern Hemisphere is 20% land and 80% water.

2

It's a moot point, and probably varies somewhat according to the state of the tide. Visually, however, the 'pole of maximum ocean' is about half-way between two atolls in the south Pacific: Tautua, 9°00' S; 157°58' W, and Starbuck Island, 5°38' S; 155°53' W. (Not that I wish to give overpriced and over-rated coffee any undue publicity!). By ...

2

(this is consciously the start of the answer - my regional geology books -cf. above comment, are packed away due to a house move). The rolling hills are very distinctive of the English Jurassic & Cretaceous. Relatively low dipping rocks - long wavelength folds. The ridges are due to rocks that are more resistant to erosion. For example, the English ...

2

I'm not sure if this is the scope you're looking for but a large portion of site analysis using GIS is to examine potential risks of natural disasters. Mass wasting risk maps based on topographical and soil characteristics as well as extreme precipitation events is a pretty standard research topic. Using fuzzy/boolean multi-criteria analysis, determining ...

2

Terrestrial laser scanning (the ground-based version of Lidar) provides very precise mapping of surfaces. This has been used to look for changes in cliff faces and slopes that are precusors to failure.

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