Scientists with the U.S. Geological Survey (USGS) reported that the South Whidbey Island Fault, capable of producing a disastrous magnitude-7.5 earthquake, may extend to North Bend.

In National Seismic Hazard Maps released April 23, the USGS increased its estimate of the length of the fault line, Washington’s most dangerous, by about 15 miles.

More than 1,000 earthquakes occur in Washington every year, and earthquakes are a serious threat in 46 of the United States, according to the USGS.

The hazard maps, which are revised about every six years, display earthquake ground motions for various probability levels across the country, and are used for determining building codes, insurance rate structures, risk assessments, and other public policy.

• More information about the fault line and earthquake preparedness is available online at www.usgs.gov.