MAY 22, 2015
LAS VEGAS, NEVADA (FOX5)
After an earthquake prompted the closure of several flyover
ramps in Las Vegas' Spaghetti Bowl interchange on Friday, transportation
engineers said the bridges remain safe for travel.
The magnitude-4.8 earthquake happened at 11:47 a.m., and was
centered in Caliente, NV, about 150 miles north of Las Vegas.
Immediately after the temblor, emergency crews shut down the
ramps from U.S. Highway 95 southbound to both directions of Interstate 15. The
Martin Luther King Jr. Boulevard ramp to I-15 southbound was also closed. This
allowed crews to inspect a gap that appeared in the 95 ramp to I-15 southbound
after the quake.
According to Mary Martini, District I engineer for the
Nevada Department of Transportation, the gap existed before Friday's
earthquake, but the tremor shook loose a protective rubber casing that was
covering the seam of the bridge, making the damage appear worse than it really
was.
“We're issuing an emergency contract to repair the seam,”
Martini said. “Meanwhile, the ramps remain structurally sound and safe for
travel.”
The ramps, which Martini said are made of cast-in-place
concrete and steel reinforcements, reopened just after 4 p.m. They will remain
open through Memorial Day, Martini said.
Several FOX5 viewers called the newsroom and posted on
social media about the quake, saying they felt buildings sway and houses shake.
One person said they heard a building creaking during the tremor.
Officials said no injuries or other significant damage was
reported.
Graham Kent, director of the Nevada Seismological
Laboratory, said Southern Nevadans shouldn't be shocked by Friday's earthquake.
“At one level, it's always a surprise when we get an
earthquake, but this area carries enough tectonic strain, as they call it, or
motion where these types of earthquakes or larger ones would not be
unexpected,” Kent said.
Nevada is the third-most seismically active state. Nearly 20
percent of the earthquakes in the United States occur in Nevada, but most are
small and centered in remote areas.
Kent said the odds of Friday's quake being a precursor to a
larger one aren't all that long.
“The standard seismologist answer is about one in 20 for
this being a foreshock of a larger earthquake, but if you look at the Nevada
record over the last 150 years, we've had an abundance of doublets and
triplets,” he said. “If you just use Nevada as an estimator, it's usually one
in five or one in four odds of having an equal or larger earthquake in the next
several days or weeks.”
If a bigger quake struck closer to the metropolitan area,
there could be substantial damage.
“The Las Vegas Valley has an uncanny ability to trap seismic
waves in a way similar to other basins like you might see in Mexico City or
Katmandu. If you're gonna punch a lot of energy into the Las Vegas basin, it's
gonna resonate for a while,” Kent said.