How thick is the Earth's Crust?

Question

How thick is the Earth's crust compared to the rest of the planet. What percentage?

Answer 1

about 7 miles

Answer 2

As noted, the crust is anything from about 8km to 70km or so. But beneath that crust, the earth is just a solid as above it. That is the beginning of the "mantle". But although your 300 miles is off target for the crust, there is a zone at about 120km where the rock is much weaker. The rock gets hotter as it gets deeper, reaching tempreatures that would easily melt rock at the surface. But pressure also increases with depth, so the melting point of the rock increases, keeping it solid. But at this weak zone, the temperature and the rock melting point come close, so the rock is "softened". It is on this weak layer that the plates move. The crust sit atop the plates, and goes along for the ride. Below the weak layer is more solid mantle, though it is still able to creep, very slowly. About 3000km from the centre, there is a sharp change to the core, known to be liquid and deduced to be made of iron. In the centre of this a ball of solid iron about 1000km across.

Answer 3

.

Earth's Crust, Lithosphere and Asthenosphere

This drawing shows the Earth's lithosphere (crust and upper mantle) on top of the asthenosphere. ... are made up of the Earth's crust and the upper part of the ...

windows.ucar.edu/tour/link=/earth/interior/earths_crust.html&edu=high - 14k - Cached



The Earth's Crust

How Thick Is the Earth's Crust?



We present a new contour map of the thickness of the Earth's crust. We use a 10 km contour interval plus the 45 km contour. This contour map was created directly from the 5 deg. by 5 deg. gridded crustal model CRUST 5.1 (Mooney et al., 1998) plus complimentary information. An initial contour map was created using the command "grdcontour" in GMT, and the resultant map was adjusted in Adobe Illustrator to honor individual point measurements and newly available information from Russia. The final contour map honors all available seismic refraction measurements for features with a dimension greater than 2 degrees. To a first approximation, the continents and their margins are outlined by the 30 km contour. That portion of the continental interior enclosed by the 40 km contour, and regions with crustal thickness of 45 to 50 km are found on all well surveyed continents (i.e., North and South America, Australia, and Eurasia). Continental crust with a thickness in excess of 50 km is exceedingly rare and accounts for less than 10% of the continental crust. These observations, now available on a global basis, provide important constraints on the evolution of the crust and sub-crustal lithosphere.

A Contour Map of the World's Crustal Thickness



This contour map of the thickness of the Earth's crust was developed from the CRUST 5.1 model. The contour interval is 10 km; we also include the 45 km contour for greater detail on the continents.

Answer 4

it depends on a few things: whether the crust is continental or oceanic, whether you ask a geophysicist or a geochemist... the general consensus is that Earth's crust varies in thickness from 5-10km under oceans to 20-50km on continents, so lets say an average thickness of 15km out of a radius of 6378km gives you a percentage of 0.3%.

Answer 5

if the world was an apple.... (whirling silently in space) It's reckoned the 'crust' is less than the depth of the apple's skin (comparatively speaking) and the atmosphere..only just a tiny bit more. Shows how fragile our existence is.

Answer 6

It depends whether the crust is continental or oceanic. Continental is normally between 30-40km. Oceanic is between 6-10km.

Answer 7

Crust is thin...about 7 miles.

Answer 8

mean thickness = 24 mi (40 km), standard deviation is 5.4 mi (9 km).



thinnest = approx 9 mi (15 km)



thickest = 47 mi (75 km)

Answer 9

not very