Document-Based Questions - Debra J. Housel, M.S. Ed. 2008

The Great Alaskan Earthquake of 1964
Incredible Disasters

The strongest earthquake ever to strike North America happened in Alaska on March 27, 1964. It struck at 5:36 p.m. and measured 9.2 on the Richter scale. The earthquake caused a lot of damage to the city of Anchorage. In some places the soil changed to a liquid form. This fluid state only lasted for three minutes. But during that time a chunk of downtown slid into the sea! It also wrecked phone, water, sewer, electrical, and gas lines.

Huge fissures opened in the ground. Some were 12 feet deep and 50 feet wide. Cars and people fell into them. One newspaper editor ran out of his home. A fissure opened beneath him. He struggled to climb up the soft, unstable dirt wall. As soon as he reached the surface, the crack slammed shut.

Whole buildings fell down. Concrete slabs broke free of the buildings. They crushed the cars and trucks below. Anchorage’s downtown area was flattened. Nothing was left standing. Outside of town, landslides buried buildings. Big oil tanks blew up. Several schools caved in. Fortunately no children were inside.

For five minutes the ground shook. Huge waves rolled in from the sea. They pounded towns on the coast. One wave was 220 feet tall! It swallowed a dock and the 12 men on it. Another wave picked up a fishing boat and threw it onto a school’s roof one-half mile inland. These tsunami waves caused 90 percent of the deaths.

Near the epicenter, the sea floor rose more than 30 feet. Latouche Island in Prince William Sound moved 60 feet west. The whole city of Houston, Texas, rose four inches. And it’s 3,300 miles away!

It was a good thing that Alaska didn’t have a big population. Although 131 people died, the death toll would have been much worse in another state. Damage costing more than $400 million covered an area of about 50,000 square miles. For days after the major quake, the people felt 100 small tremors a day. Tiny aftershocks continued for a year.

The Great Alaskan Earthquake of 1964

Seismographs are instruments that record the size of an earthquake’s shock waves. They tell scientists the strength of a quake on the Richter magnitude scale.

Adapted from U.S. Geological Survey documents.

“Richter Magnitude Scale.” http://en.wikipedia.org/wiki/Richter_Scale

The Great Alaskan Earthquake of 1964

1. Most of the deaths caused by the 1964 Alaskan earthquake were due to

a. schools and other buildings caving in.

b. oil tanks blowing up.

c. landslides burying buildings.

d. tsunami waves coming ashore.

2. A fissure is

a. an earthquake’s epicenter.

b. the strongest shaking during an earthquake.

c. a big crack in the ground.

d. another name for a tsunami.

3. The 1964 earthquake was so strong that

a. an island sunk under the waves.

b. a city far away was pushed up.

c. it cracked every road in the state of Alaska.

d. a new mountain range was formed.

4. According to the Richter scale, an earthquake with a magnitude of 7.4 is called Strong. True or False? Explain.

5. According to the Richter scale, what is the name of the strongest kind of earthquake and was the 1964 Alaskan earthquake one of these? Use facts from the chart in your answer.

6. Would you be afraid to live in an area that has earthquakes? Why or why not?