Answer:
Option b, pothographs from drones.
Explanation:
the USGS (U.S. Geological Survey) decided to make photographic captures from drones to the volcanic surfaces, which allowed through observations to understand things like the characteristics of the lava, the height of the volcanic plumes (among others).
Podemos ver en el siguiente enlace un ejemplo de fotografía tomada desde un dron al Kilauea.
https://www.usgs.gov/media/images/k-lauea-volcano-drone-over-lava-channel
The study of EM is essential to understanding the properties of light, its propagation through tissue, scattering and absorption effects, and changes in the state of polarization. ... Since light travels much faster than sound, detection of the reflected EM radiation is performed with interferometry.
Convex Lenses are used to focus light and form a image. They are transparent.
They are one type of lenses. Different type of lenses are used to focus light differently. The basic lenses are concave and convex. Convex lenses converge light falling on it whereas concave lenses diverge light falling on it.
Speed v = distance travelled / time taken
v = d / t
v = 540 / 60h
v = 9 km /h
