<span>Guyots are seamounts that have built above sea level. Erosion by waves destroyed the top of the seamount resulting in a flattened shape. Due to the movement of the ocean floor away from oceanic ridges, the sea floor gradually sinks and the flattened guyots are submerged to become undersea flat-topped peaks.</span>
Because it would require more energy to create elements with more protons
Answer:
Seafloor spreading results from intense activity in the upper mantle which cracks the crust and pushes it away.
Explanation:
Seafloor spreading is a process that was first noticed by Alfred Wegener and was used by him in his theory of plate tectonics. There are three types of plate boundaries; convergent boundary, transform boundary, and divergent boundary. The last one is the one where seafloor spreading occurs.
The convection currents in the mantle are the process that breaks up the crust and move the tectonic plates, and when there is higher activity than usual at some place it results in break up the crust of an already existing tectonic plate. Basically, magma rises at a higher rate and pushes through the crust, in this case, the oceanic crust, and it manages to gradually break through it and come out on the seafloor. By doing so, the magma and the pressure from below are pushing the two now divided parts of the plate. As the space between the two different parts becomes larger and large the density of the crust becomes smaller and smaller so more and more magma rises through. The magma quickly solidifies on the ocean floor and piles up, thus creating an underwater mountain range known as a mid-ocean ridge.
Answer:
Human activity - Produces greenhouse gasses.
Greenhouse gasses - Cause atmosphere to trap more heat.
Sun's output - Can vary.
Ice age - Peaked 20,000 years ago.
Explanation:
Human activity includes the usage of fossil fuels on a very large scale, and by using them we release huge amounts of greenhouse gasses into the atmosphere.
The greenhouse gasses have the ability to trap the heat that is reflected from the surface of the planet, thus keeping more of it in the atmosphere and causing global temperature rise.
The sun is technically a star, thus an object that produces energy and light, and like every star, it has variations in its activity in accordance with the processes going on on it.
There have been numerous ice ages through the geological past, and the last one of them ended only around 10,000 years ago, with its peak being just 20,000 years ago.
<span>True, however 50% is rather optimistic value, it's probobally more. The main source of water is in the ground and the groundwater gets constantly more contaminated with road salt, oil, gasoline and other chemicals (and as you can see, these are all manmade products).</span>