system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do they calculate volumes of lakes and oceans when the depth is inconsistent and the shape is irregular?
gpt
For lakes they do extensive charting. You can look up Great Lake charts and see that they have depth readings throughout the entire lake. From there, they can estimate the volume by assuming some gradient between the locations of their readings. The more readings that are taken, the more accurate the estimation will be. It’s probably similar for oceans.