Most earthquake deaths result from collapsing buildings and objects. Stronger buildings are the best safeguard, but the steep cost makes them an unrealistic option for cash-strapped regions. Read more →
On May 2, a rare earthquake shook Michigan, rolling in at magnitude 4.2, the second strongest quake recorded in the state. Fortunately, although items fell off of shelves and windows vibrated, the state suffered no major destruction or injuries from the quake. Read more →
Almost every day for the last five months, hundreds of small earthquakes have rattled Axial Seamount, an underwater volcano located three hundred miles off of the Oregon coast. At the same time, underwater pressure sensors have revealed that the surrounding seafloor had been slowly rising. Then, on April 24, almost eight thousand earthquakes rumbled Axial and the seafloor dropped almost eight feet! Read more →
By combining data about surface mineral resources, national-scale gravity and aeromagnetic surveys, and the age and origins of basement rocks, the USGS has developed a map of the basement rocks underlying the United States. Basement rocks sit above the mantle but beneath all other rocks and sediments. The full report is available here. Read more →
Will the Yellowstone magma chamber--make that chambers--ever stop growing? Well, they're not actually growing per se; rather, scientists are discovering that Yellowstone's magma chambers are bigger--and more numerous--than previously believed. In 2013, the upper magma chamber was revealed to be more than double its previously estimated volume. Then, this month, geophysicists announced the existence of an additional, deeper, larger magma reservoir sitting between the upper chamber and the mantle plume feeding the legendary volcano. Check out the video below, by the University of Utah, to see a 3D animation of the setup. You can read more about Yellowstone eruptions in my previous post, which has been updated. Read more →
During the age of the mammoth, a hominin roaming southern Italy stumbled into a hole in the karst landscape. Out of reach of sun and predator, he starved to death, his body decaying and his bones slumping into a pile, mineral-rich waters ultimately calcifying and fusing them into the surrounding limestone. Locked in the limestone, his skeleton would remain there until 1993, when cave explorers found his face--upside down--staring back at them. Read more →
An unconformity is an erosional surface between strata. Since they usually form when the older (lower) layers are exposed and eroded, unconformities can tell us about the history of the rock, but sadly, they can also erase millions of years of evidence. There are three main types.
Long viewed as a cold dead rock devoid of lava for a billion years, new evidence suggests that the moon could have seen small surface flows as recently as 20 million years ago. Twenty million years might not seem recent, but considering the moon and earth both date around 4.5 billion years old, 20 million years represents 0.4% of its age, or what 5 months is to a 100-year human lifespan. In that sense, the new findings are like discovering the moon was alive 5 months ago! Read more →