Shallow fault puts Newport-Mesa on shaky ground

Paul Clinton

NEWPORT-MESA -- The rumbling, deep earthquake that rocked Seattle

would have caused significantly more damage if it had hit closer to

Newport Beach.

An earthquake with a comparable 6.8 magnitude would have rumbled much

closer to the ground’s surface if its epicenter was on the

Newport-Inglewood fault -- which stretches from Beverly Hills to Laguna

Beach, including Costa Mesa and Newport Beach.

State quake expert Tousson Toppozada, who wrote a 1988 report on the

fault line, said Seattle defied expectations, with only one person dying

in the disaster, because the quake’s epicenter was buried 30 miles

underground.

“If we got the same quake we saw in Seattle, you’d see more damage

here because the focal depths are shallower,” said Toppozada, a senior

seismologist at the state’s Division of Mines and Geology. “They’ll be

more like five to 10 miles deep.”

In the 1988 report, Toppozada laid out a “worst case scenario” quake,

with a 7 magnitude, on the Newport-Inglewood fault line to help public

agencies prepare for such an event.

Toppozada’s projection wasn’t based on fantasy. He based his study

partly on the 1933 Long Beach quake, whose epicenter was off the Newport

Beach coastline.

Other quakes on the fault line include one of a 4.9 magnitude in

Inglewood in 1920 and a pair of 4.7 to 5 magnitude quakes in 1941 in

Dominguez Hills.

In addition to the depth factor, California quakes also tend to move

differently. Fault lines closer to home tend to shift laterally, a

movement known as a “strike slip.”

Faults in the Pacific Northwest tend to move up and down in a rocking

motion, Toppozada said.

Public safety officials in Newport Beach and Costa Mesa are always

prepared for earthquakes and other emergency situations, Newport Beach

Emergency Services Coordinator Donna Boston said.

Each city department has been given a specific set of guidelines to

follow when quakes occur.

“We’re constantly polishing the way we would handle a situation” where

a quake occurs, Boston said. “We’re very well-prepared and

well-practiced.”

FYI

Earthquake Tips

* Bolt older houses to the foundation.

* Board or place protective tape on windows and glass doors to

minimize flying glass.

* Strap mobile homes to their concrete pads.

* Anchor such furniture as bookshelves, hutches and grandfather clocks

to the wall.

* Secure appliances and office equipment in place with

commercial-strength Velcro.

* Secure cabinet doors with childproof fasteners.

* Locate and label gas, electricity and water shut-offs before

disasters occur. After a disaster, shut off the utilities as needed to

prevent fires and other risks.

* Store a shut-off wrench where it will be immediately available.

* Secure water heaters to the wall to safeguard against a ruptured gas

line or loose electrical wires.