A physicist may study the optical properties of glass and other transparent materials. But the type of glasses you wear on your nose are usually not handled by scientists, but by opticians.
Volcanologist.
A paleontologist would generally study paleontology.
The type of investigation would be fieldwork.
Geologist - specifically a 'Vulcanologist'
a physicist
An archaeologist
zoologists
Geologists study the Earths surface
BIOLOGISTS ...
all of them
oceanagrapher
It wouldn't be a chemist; a type of scientist called a petrologist or mineralogist studies rocks and their minerals.