Alaskans, along with the rest of the world, were shocked as they watched the news coverage of the massive destruction after an earthquake leveled nearly all of Haiti.

As they saw the devastation, a little niggle of worry wormed its way into the minds of many in Alaska. Could that happen here?

Certainly, dozens of earthquakes are recorded in Alaska every day – more than in the other 49 states combined – though most go unnoticed. Still, the largest quake ever recorded in the United States struck Southcentral Alaska in 1964. The Good Friday quake, registered at magnitude 9.2, caused a huge tsunami, and both resulted in massive destruction all down the West Coast.

In fact, seven of the top 10 of the nation's largest earthquakes happened in Alaska, according to the U.S. Geological Survey.

There are mountains of books that specify a huge laundry list of building codes intended to ensure that construction projects are built to withstand earthquakes.

Contractors follow building codes based on observations from California earthquakes, codes that may not fit the conditions that hit during quakes in Alaska, according to an earthquake researcher at the University of Alaska Anchorage.

Alaska is prone to earthquakes that last longer than those in California, said UAA School of Engineering professor He Liu. Current international building codes are based on data collected from earthquakes in California, but Liu said buildings in Alaska can suffer in ways not accounted for in the California data because the quakes sometimes last longer.

Anchorage sits atop what is known as a subduction zone, meaning that when tectonic plates collide, one tends to slip beneath the other rather than the two simply rubbing together. This produces a longer, more sustained earthquake, like the one in 1964.

Since that earthquake struck Anchorage, the city's population has grown considerably, said Utpal Dutta, an associate professor at UAA's School of Engineering. With an increase in the number of people comes an uptick in the construction of new buildings, meaning the stakes rise as a larger urban sprawl must be considered when planning for an earthquake.

The codes also don't account for ground failure, a condition under which the shaking of the ground in an earthquake affects its stability, said Ron Wilde, a plan review engineer with the municipality of Anchorage's Department of Public Works.

In the early 1990s, the Alaska Science and Technology Foundation awarded UAA a grant to install sensors within the Anchorage Bowl with the purpose of monitoring earthquakes and determining how they affect the ground, Dutta said.

UAA installed 22 sensors under the grant. In 2002, the U.S. Geological Survey installed 20 more. All of these sensors work around the clock to monitor ground movement during earthquakes.

In 2004, the U.S. Geological Survey installed equipment on four buildings to see how they would react during an earthquake, including the Port Access Bridge and the Robert B. Atwood Building.

According to a "shake" map based on data collected from these sensors, Anchorage is separated into different zones, depending on how the ground in an area tends to react during earthquakes.

The west side of town is classified under the "D" category, with the east side classified under category "C." A building on category "D" land is likely to shake harder and suffer more damage than an equivalent building on category "C" land.

Though Dutta said UAA is in constant contact with the city government of Anchorage to inform them of seismic hazards from potential earthquakes, Wilde said the building standards used by Anchorage and every major city in the nation are not designed with this research in mind.

Instead, building codes are derived from a book released from the International Code Council, with residential one- and two-family dwellings adhering to codes derived from the International Residential Code.

Codes also are derived from the American Society of Civil Engineers' Minimum Design Loads for Buildings and other Structures and the Seismic Design Manual put out by the American Institute of Steel Construction.

Before constructing a building, a developer or construction firm must obtain a permit from the city. Inspectors often go to work sites and buildings and ensure that they are built in adherence with these codes.

In preparing a building to survive an earthquake, the main focus is on ensuring that the building acts as if it were one contiguous piece, rather than several pieces that can shake independently of one another.

To that end, builders in Alaska are asked to install various components on buildings that help mitigate earthquake damage, including steel braces and plywood shear walls. The shear walls are often held in place by holdowns, metallic pieces that connect the bottom of the shear wall to the ground.

Officially, the municipality of Anchorage separates the city into three letter categories: "B," "C" and "D." Category "B" land is the least affected by an earthquake, whereas category "D" land is more affected.

Though building codes are subject to change as more is learned about earthquakes and how buildings are affected by them, Wilde still thinks Anchorage is essentially ready for the next quake. He also believes current codes are adequate.

Sean Manget can be reached at

sean.manget@alaskajournal.com.