This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Old Faithful eruptions graph. Waiting time between eruptions and the duration of the eruption for the Old Faithful geyser in Yellowstone National Park Wyoming USA en Nwstephens en Nwstephens Original upload log en Oldfaithful bytes Nwstephens no time between eruptions and the duration of the eruption for the Old Faithful