<span>
Earthquake-</span><span>a. measured on the Richter scale
</span><span>
Volcano-</span>b. lava comes out d. forms a mountain<span>
Both-c</span><span>. natural hazard
d. caused by subduction</span><span>e. occurs underwater
f. measured using a seismograph</span>
Basalt is the rock that makes up a majority of the oceans floor!
Th answer you are looking for is physical weathering