Friday, May 22, 2015

4.8 Earthquake In Rural Nevada, Felt In Las Vegas

Magnitude-4.8 Earthquake in Rural Nevada Felt in Las Vegas; Freeway Ramps Temporarily Closed | KTLA

A magnitude-4.8 earthquake that struck late Friday morning in Nevada near the Utah border was felt in Las Vegas, some 80 miles away, and several freeway ramps in the city were closed amid reports of damage.
The quake struck at 11:47 a.m. about 60 miles west-northwest of St. George, Utah, according to the U.S. Geological Survey.
The USGS gave the nearest town as Caliente, about 24 miles north-northeast of the epicenter, which was in a remote mountainous region about 100 miles driving distance from Las Vegas.
The quake hit at a depth of 2.6 miles. It was initially reported as a 5.4-magnitude temblor, but that was later changed to a 5.3, and then to a 4.8.
The temblor caused the rubber encasing to separate on the bridge of a freeway interchange ramp from U.S. 95 southbound to the southbound Interstate 15. The ramp was shut down for inspection, along with two others.
“The joint damage was pre-existing. The tremblor (sic) simply dislodged the protective rubber encasing the bridge seam making it look much worse than it was in reality,” a Nevada Department of Transportation district engineer said in a news release.“However, we’re issuing an emergency contract to repair the seam. Meanwhile, the ramps remain structurally sound and safe for travel.”
The ramps reopened before 5 p.m. Friday and were slated to remain open throughout Memorial Day weekend.

Sections of the Spaghetti Bowl that were closed for inspection after Friday’s earthquake were reopened just before 5 p.m., according to the Nevada Department of Transportation.
A 4.8-magnitude quake shook Las Vegas and surrounding areas Friday morning, and the state closed parts of the U.S. Highway 95 and Interstate 15 interchange for several hours to inspect ramps for possible structural damage, backing up traffic for miles.
The quake, which hit at 11:47 a.m., was centered about 23 miles south-southwest of Caliente, the U.S. Geological Survey said. The magnitude was originally reported as 5.4, but the official number was lowered twice Friday afternoon.
The ramp from southbound U.S. Route 95 to southbound Interstate 15 was closed about 12:20 p.m. Friday, NDOT said. But after inspection, the state determined the roadway was safe for travel.
“The joint damage was pre-existing. The tremblor simply dislodged the protective rubber encasing the bridge seam making it look much worse than it was in reality” and prompting an immediate shutdown of the ramps, NDOT engineer Mary Martini said in a release about 3:45 p.m.
An emergency contract was issued to repair the seam, but the ramps are structurally sound, Martini said.
The southbound U.S. 95 and Martin Luther King Boulevard on-ramps to southbound I-15 were also closed as a precaution, the release said. NDOT tweeted at 4:53 p.m. that all ramps were open.
The I-15-U.S. 95 interchange is the busiest stretch of road in the state, with 250,000 vehicles a day traveling through it — a number that could be even higher this weekend, NDOT spokesman Tony Illia said, as an extra 198,000 drivers come to Las Vegas for the holiday weekend.
Meanwhile, the Highway Patrol was checking for possible damage at other major freeway interchanges, Trooper Loy Hixson said.
Illia said Nevada has some of the best-rated bridges in the country, according to a recent report by the American Road and Transportation Builders Association. Only 1.8 percent of Nevada bridges are classified as structurally deficient, which is the lowest in the country. The national average is 6 percent.

The USGS reported four significant aftershocks, with magnitudes 3.8, 3.0, 3.4 and 2.5, between 12:05 and 12:58 p.m.

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