Northern Illinois quake rattles homes, Fermilab equipment
|The plot shows the results from tilt meters strapped to Tevatron magnets that recorded the slight back and forth motion of the magnets due to the earthquake. The large light-blue area shows the beam prior to the earthquake. The light-blue lines stop when the earthquake began.
At 3:59 a.m. this morning, a 3.8-magnitude earthquake shook northern Illinois. The epicenter of the quake was located close to Gilberts, Ill., about 34 miles from Aurora.
A 5.2-magnitude quake hit downstate Illinois in April 2008. This morning's quake was the second worst to hit Illinois since 1968. Residents felt its vibrations across northern Illinois and into parts of southern Wisconsin.
Tilt meters strapped to Fermilab's magnets recorded the vibrations at the laboratory. The earthquake shook the magnets and caused the beam to strike a collimater, losing its store.
The Tevatron operations crew planned to dump the beam around 6 a.m. in order to gain access to the tunnel, so although the earthquake caused loss of the beam, it didn't hamper operations.
The plot shows the slight movement of the Tevatron magnets tilting back and forth at the time of the quake. The quake can be seen in the vertical section of the center of the plot. The large light-blue area on the left side of the plot indicates the beam, which halts at the time of the quake.
-- Rhianna Wisniewski
Read more about the quake in today's Chicago Tribune.
View statistics about the quake on the USGS site.