Is the earth lithosphere thicker at ridges or trenches?

What term is given to the border between the central alps and the southern limestone alps?

One of the brightest comets of the 20th century was comet hyakutake, which passed close to the sun in early 1996. the orbital period of this comet is estimated to be about 30,000 years. find the semi-major axis of this comet’s orbit. compare it to the average sun-pluto distance and to the distance to alpha centauri, the nearest star to the sun, which is 4.3 light-years distant.

Which characteristics of temperature and salinity have the greatest influence on the movement of deep-ocean currentsa. warm and low salinityb. cold and high salinityc. cold and low salinityd. warm and high salinity