The cities of Dallas and Irving took a first step toward an earthquake task force Monday with an afternoon conference call that included experts from the US Geological Survey. Seventeen small quakes have hit the Irving area around state highways 114 and 183 in the past week. Several of them were big enough to startle neighbors in Dallas and elsewhere.
At a Monday morning Dallas City Council update on the series of earthquakes that have shaken windows and rattle nerves, Councilwoman Jennifer Gates said she never would have imagined.
“If somebody had told me my first year we would be dealing with earthquakes and Ebola, I would have been a little bit surprised that would be Dallas and District 13," Gates said.
That district stretches from Webb Chapel on the west to Vickery Meadow in East Dallas. Constituents living closest to Irving reported feeling several of the quakes.
Rocky Vaz, director of the Dallas Office of Emergency Management told council members a primary goal of the task force would be getting the latest, accurate information on the earthquakes to the public, and educate them what to do when the ground starts shaking.
“Drop, duck, cover. Get under a table," Vaz said. "If you’re inside of the house stay inside don’t run out. If you’re outside, stay away from electric poles or tall buildings. Be in an open area.”
Dallas Council members asked city officials if the building codes need to be updated. Building Code Administrator David Session says there have been some seismic standards on the books since 2002.
“Based on the historical situation that we’ve been in, the requirements are minimal,” Session said.
He can’t say what ‘magnitude’ might trigger a review and possible upgrade of building codes. He says the measurements are different.
“Richter scale is more of a measure of intensity of the event itself," Session said. "Building code is actually dealing with the horizontal ground motion which is where the major damage comes from as far as the building is concerned. In the Dallas area that motion is so minimal the code doesn’t trigger any major requirements as it would do, let’s say, in California."
Rocky Vaz told council members the likelihood of a North Texas magnitude 5 earthquake – the threshold for serious damage – is .023, very small. The strongest quake so far has been 3.6. In Irving, where most of the quakes have been recorded, the City Council gets an update from SMU seismologists Thursday.