topologi.es | Articles | Topics Research Suggests Machu Picchu Was Purposely Built on Top of Intersecting Fault Lines smithsonianmag.com | Submitted 4 years ago The Mount St. Helens Eruption Was the Volcanic Warning We Needed nytimes.com | Submitted 4 years ago A chunk of Yellowstone the size of Chicago has been pulsing. Why? nationalgeographic.com | Submitted 4 years ago Back home