Once again i need help with these?

Question

What specific instruments were needed to gather each of the following types of data?

(a) demonstration of the ruggedness and youth of the ocean floor

(b) confirmation of repeated reversals of the Earth's magnetic field in the geologic past

(c) emergence of the seafloor-spreading hypothesis and associated recycling of oceanic crust

(d) precise documentation that the world's earthquake and volcanic activity is concentrated along oceanic trenches and submarine mountain ranges

Answer 1

a shovel helped

seismograph

sonar

depth finder

compass,

altimeter

and a lot of other stuff