Paragraph 2
Professor Seo explained how
affects Earth's
. He said: "Every mass moving around on the surface of the Earth can change the
axis." Scientists have only recently discovered how groundwater can change Earth's
. They previously believed water-driven
were caused by melting glaciers and ice
. Seo and his colleagues were puzzled at how this could cause such a tilt. They concluded that the
of underground water was also a factor. Much of the extraction of groundwater is due to
, especially in north-western India and western North America. Another
said: "The very way the planet wobbles is impacted by our
."
