Tag Archive for: hazard


A series of massive volcanic eruptions between eight and 12 million years ago in what is now Idaho may have been larger than colossal events known to have taken place in Yellowstone.


While the risk of the Yellowstone Supervolcano erupting remains unchanged, researchers have found that its got another larger magma chamber. Read more!


Yellowstone’s underground plumbing is becoming more clear.


By: William R. Lund

The Utah Geological Survey has revised and updated the Utah fault database used with the Federal Emergency Management Agency’s Hazus Earthquake Model. The Hazus Earthquake Model loss estimation software is designed to produce loss estimates for use by federal, state, regional, and local governments in planning for earthquake risk mitigation, emergency preparedness, response, and recovery. The model’s loss estimates are based on a scenario earthquake on a fault in an area of interest. This revised Hazus Utah fault database provides parameters for scenario earthquakes on significant Utah Quaternary-active faults statewide and for select faults/fault sections in adjoining states. The previous Utah Hazus fault database contained 27 Quaternary faults/fault sections taken largely from fault sources on the United States National Seismic Hazard Maps. This revised database expands the Utah Hazus fault database to include all known Late Quaternary and younger faults/fault segments capable of generating a ≥M 6.75 earthquake in Utah, and includes 82 Quaternary-active faults/fault segments, and nine credible multisegment rupture scenarios.



The Iron County Commission was poised to vote Monday on a geologic hazard ordinance that has been in the making for about six months when Commissioner Lois Bulloch threw a wrench in the works.

Bulloch recommended that an independent group review the proposed ordinance and make recommendations.

“I’ve heard a lot of consternation over this issue and had input in letters and calls and am just not comfortable moving forward,” said Bulloch. “Sorry to drop this bomb.”

Bulloch suggested that a committee with representatives of the county’s six municipalities, a city attorney and engineers look at the ordinance line by line and make specific changes.

“This way we won’t be accused of not listening,” said Bulloch.

Bill Lund, a geologist with the Utah Geological Survey, told commissioners a review by new eyes is a good idea and recommended including an official of a city or county in Utah that has already dealt with a similar ordinance.


An upslope-facing scarp in the Springhill landslide in North Salt Lake. Additional damage to several of the houses on the landslide has resulted from an increase in the rate of movement in 2009

Local wet conditions in northern Utah have caused some landslides to reactivate along with other types of shallow slope failures. Areas with active landslides in early 2009 include Ogden Valley in eastern Weber County, western Morgan County, southeastern Davis County, and Spanish Fork Canyon in Utah County. Examples include:

1.  reactivation or acceleration of persistently moving historical landslides,
2.  minor movement of landslides in highway cut slopes,
3.  local highway embankment and rock-wall failures, and
4.  local shallow slides on steep slopes in pre-existing landslides.