occurred 44 years ago today. It was a Friday. It was in fact Good Friday. And in Alaska they experienced the full force of what the Earth can render when at 5:36 in the evening they were struck with an Earthquake.
On the Richter Scale the force of the Earthquake was 9.2. You must remember that the Richter Scale is logarithmic: that is, every whole number is a multiplier of 10. For comparisons, consider this
Oct 17, 1989 Loma Prieta Earthquake 6.9 (Alaska more than 300 times as powerful)
1906 San Francisco earthquake, as devastating as it was, only 8.3
(more)
According to the Wikipedia article, this was the most powerful earthquake ever to hit the United State, and the 3rd most powerful ever measured by seismograph. More than 130 people died from the quake and the ensuing Tsunami.
As the article notes,
The focus of the rupture was at a depth of ~25km and its duration was approximately 4 minutes. The powerful earthquake also caused some parts of Alaska to experience liquification of the soils which are mostly unconsolidated boulder clays, silts and sands (see earthquake liquefaction), causing much damage to property and leading to landslides. Large areas were uplifted about 11 m, whilst others sank underwater by similar amounts, giving a total vertical displacement of about 23 m.
(and there is a picture showing some damage in Anchorage, less than 100 miles away from the epicenter; there are at the bottom of the article more photos worth paging through).
I remember reports of the quake, ans some sense of its impact can perhaps be recognized in this brief note again from wiki:
The earthquake lasted for three to five minutes in most areas. Movement of the ocean floor generated large tsunamis with an estimated initial amplitude (height) of approximately 10 m - these surged to a height of 20 m (approximately)
And as bad as that was, consider this:
Over 10,000 aftershocks were recorded following the main shock. During the first 24 hours eleven aftershocks were recorded each had a magnitude greater than 6.0 (Richter Scale). An additional nine more large aftershocks occurred over the next three weeks. It was not until eighteen months later that the aftershocks were considered to be no longer of a dangerous magnitude.
There are limits of what we can prepare for in dealing with the impact of natural events. Certainly parts of the country experienced with hurricanes and earthquakes can have building codes that will lessen the damage these events can cause. But ultimately there is nothing we can do to totally prepare for a category 5 hurricane, an F-5 tornado, or and earthquake of the magnitude of this 1964 event. At least in the case of hurricanes we may have several days to prepare, for tornadoes to seek immediate shelter to minimize the deaths and injuries, even as we can do little on short notice to prevent extensive property damage and destruction of buildings and infrastructure.
But for an earthquake we remain strikingly at risk: we do not know all the seismic fault lines: a quake may disclose a previously unknown line, over or near which we have too many buildings and too many people.
Imagine a quake of this magnitude hitting a major city at rush hour - and remember, the Loma Prieta quake, which many of us saw live as we were tuning in to the World Series, did hit at rush hour, and was almost 300 times less intense.
I thought it worth reminding people. We are in the midst of a bitter primary battle. The stakes are certainly high. But we can anticipate, which means we should be able to act appropriately. We may be risking the future of millions or even billions of people. But we can see what is happening, and have some opportunity to act appropriately to minimize damage.
In 1964 the people of Alaska had no warning, no opportunity to prepare. That more did not die is in itself something of a miracle. And perhaps we should take a moment or two to reflect on that, on how lucky we are that we are not subjected to such events more frequently?
Peace.