1 For an observer on the ground with eye level at h = 5 ft 7 in (1.70 m), the horizon is at a distance of 2.9 miles (4.7 km). 2  For an observer standing on a hill or tower 100 feet (30 m) in height, the horizon is at a distance of 12.2 miles (19.6 km).
The mantle is a layer of the Earth between the crust and the core. The upper mantle starts below the crust and goes down to a depth of around 200 miles to the boundary with the lower mantle. The temperature of the mantle ranges from 900 degrees Fahrenheit near the crust to as high as 7000 degrees near the core.he Upper Mantle: Temperature and Depth. The upper mantle begins just beneath the crust and ends at the lower mantle. The thickness of the upper mantle is between 200 and 250 miles.
The mantle is divided into two basic parts, the outer mantle and the mantle (inner mantle). The temperature around the outer mantle is about 300 to 500 Â°Celsius. At the outer core where it bounds the mantle, the temperature is a bit short of 4500 Â°Celsius. That's a big temperature gradient.You'll find links below to relevant articles, and you'll also find that the data presented varies a bit, as it should.he mantle comprises about 85% of the volume of the earth. The core, you'll recall, is only a bit over 4,000 miles in diameter, and the diameter of the earth is a bit short of 13,000 miles.