The crustal surface varies in density—the oceanic crust is heavier than the continental crust. composition, density, and thickness. isostasy, density, and rock competence. thickness—the oceanic crust is thinner than the continental crust.

Yes, The oceanic crust is more dense but thinner than the continental crust,

Explanation:

As the continental crust is  35-40 km, more thicker than that of the oceanic crust and it accounts for a mean surface elevation of three miles. Hence the continental crust is lighter than the oceanic crust and thus the less dense crust floats or stays at the top but the thickness of the oceanic crust is 7 to 10 km. As the surface crust is a layer of the granitic and the sedimentary and metamorphic rocks and about 40% of the earth's surface is formed by this plate or continental crust and rest 60% is by the oceanic crust which is made of basalt. Both are less dense than the mantel.

Geologists use  seismic waves to  locate an earthquake's epicenter..