Earthquakes of the past hold the key to California’s future

Studying other countries’ disaster preparedness provides insight into the inevitable

When a 7.8 magnitude earthquake hit southeast Turkey and the Syrian border earlier this year, 18 million people were impacted with 55,000 dead and almost 130,000 injured. The Feb. 6 earthquake was followed by a second wave of similar magnitude, and thousands of aftershocks exacerbated the destruction that left over 170,000 buildings in ruins and only 1 in 7 health centers functional.

In the aftermath of the disaster, the Turkish government opened an investigation into over 600 contractors, building owners and officials. Turkey’s Justice Minister Bekir Bozdag stated that “the detection of evidence in the buildings continue[d] as a basis for criminal investigation.”

Of the arrest warrants issued, 184 individuals were taken into custody, including the mayor of a town that has since been closed off for the investigation. Endemic corruption and the failure to enforce the Turkish government’s building standards and conduct inspections were cited as the reason that many higher-up officials have been jailed. 

Opposition parties to President Recep Tayyip Erdogan have accused his government and regional administrations of allowing structures to be built with inadequate materials and methods. After an earthquake struck Turkey in 2011, Erdogan said that constructors’ “negligence amounts to murder.” Since, an amnesty program in Turkey allowed older, unsafe buildings to avoid costly reinforcement processes with a fee paid to the Turkish government. Now, while Erdogan acknowledged the possibility of faulty infrastructure, he said in a visit to the region that “such things,” referring to natural disasters, “have always happened.”

Jonathan Stewart, a professor of civil and environmental engineering at the UCLA Samueli School of Engineering, acknowledged that the 11 Turkish provinces impacted by the earthquake are in a region highly susceptible to seismic activity. While Stewart believes that Turkish building codes are appropriate for the area, he is open to the possibility that construction flaws or the skirting of building codes played a role in the widespread damage.

“Typically in Turkey there are reinforced concrete buildings, which tend to be taller, and masonry buildings,” Stewart said. “Masonry buildings are usually highly vulnerable to earthquakes.  Reinforced concrete buildings can be safe if they are well-designed and constructed, or can be very dangerous if that is not the case.”

The North Anatolian Fault in Turkey is comparable to the San Andreas Fault in California. Both are considered long strike-slip faults, a classification that determines the type of earthquake likely to occur and its magnitude. The high slip rate of the respective faults, or the velocity at which one tectonic plate moves in relation to another, also leads to the geological pattern of a predictable earthquake every few hundred years. 

“[The earthquake in Turkey] was a very powerful earthquake with many structures close to the fault,” Stewart said. “In that sense, it is an exceptionally unfortunate circumstance in terms of seismic demand, but not unlike what we expect to see in portions of California for future events.”

Importantly, there are major metropolitan areas near both fault systems, which can produce catastrophic destruction when seismic events occur. The last major earthquake on the Californian San Andreas Fault was 150 years ago, in 1857.

In response to the threat of earthquakes, California’s Seismic Safety Commission has developed a building code that, according to a study, “allows damage, which means buildings may not be habitable or functional after a moderate or large earthquake.” While building or reinforcing structures that are still likely to collapse in an earthquake may seem counterintuitive, it’s an infrastructure strategy that has been developed to prioritize life safety. In recent years, Los Angeles lawmakers have put forth legislation to save buildings as well as lives, citing that the impact a completely collapsed metro area would have on the state’s economy and long-term living conditions is too great a risk to contend with.

Stewart has studied earthquakes of similar scale in other countries with similarly sized buildings and conditions to Turkey and California. He pointed to events like the 9.0 magnitude Tohoku earthquake off the coast of Japan in 2011 and the 8.8 magnitude Maule earthquake in Chile in 2010.

“The shaking intensities for the events in Japan and Chile were generally lower in amplitude, although longer in duration,” Stewart said. “Relative to this earthquake in Turkey, the performance of structures in those events was quite good. Both Japan and Chile are known to have quality building codes and good enforcement.”

Studying earthquakes of the past and present supplies scientists, legislators and construction workers with the tools to develop better disaster preparedness before an earthquake occurs and efficient, life-saving response tactics when one does. Scientists warn that improved infrastructure is imperative not only in high-risk areas for major seismic activity like California, but for the potential of natural disasters all around the world.“It is critical that we collect valuable and perishable data following the disaster in Turkey and Syria,” Stewart said, “so that we may learn from it and reduce long-term seismic risk in seismically vulnerable regions globally.”