The April 2009 Earthquake in L'Aquila, Italy



Introduction:


In April 2009, an earthquake struck the town of L'Aquila, Italy. It's devastation was experienced for miles from the epicenter. The earthquake happened just a short time after warnings of a large quake were posted on the internet by an Italian technician. Could this earthquake have been predicted and prepared for? Could lives have been saved had the technicians warnings not been ignored? This Wiki page is designed to study the L'Aquila earthquake and the preceding threats made known by the Italian technician. This Wiki will describe the very controversial assertions that this earthquake was a predicted event and critically assess the statement and its believability.

Background Information:


Basic Details:

On Monday, April 6, 2009 a devastating earthquake rocked the town of L'Aquila, Italy. Italy is one of the most earthquake prone areas in all of Europe and is often experiencing tremors, large and small. The exact location of the earthquake in latitude and longitude was 42.334°N, 13.334°E. The earthquake occurred at 3:32:39 in the morning at the epicenter and was felt in large waves as far as 60 miles away in Rome, Italy. The violent shaking and destruction was also felt in an approximate 26 other cities. The quake was measured at a magnitude 6.3 on the Richter scale. This can be seen in Figure 1. The depth of the earthquake was recorded at 8.8 km (5.5 miles).
map_of_quake.jpg
Figure 1 is a map depicting the geographic location of the earthquake and the 6.3 magnitude measured on the Richter Scale (http://www.nytimes.com/2009/04/07/world/europe/07italy.html)

The L'Aquila earthquake occurred as a result of normal faulting on a Northwest-Southeast oriented structure in the central Apennines. The central Apennines region is complex, including the "subduction zone of the Adria micro-plate beneath the Apennines from east to west, continental collision between the Eurasia and Africa plates, and the opening of a valley called the Tyrrhenian basin". The April 6, 2009 earthquake was a response to the Tyrrhenian basin opening faster than the compression between the Eurasian and African plates. Deaths were reported in the surrounding towns and villages of Castelnuovo, Poggio Picenze, Tormintarte, Fossa, Totani and Villa Sant'Angelo.The earthquake happened hours after a 4.6-magnitude tremor shook the area but caused no reported damage.Thousands of the city's 70,000 residents ran into the streets in panic following the 30-second tremor. Survivors described finding themselves looking out on to open streets as the walls of their buildings fell away. Some of the measurements recorded from the earthquake at Keele University can be seen below in Figure 2. Notice the arrival times of the P (primary) and S (secondary) waves. The P wave arrives first, creating some movement as a precursor to the S wave. As the S wave arrives, the shaking gets more violent. A large amount of shaking can be felt for about 10 minutes followed by numerous dangerous aftershocks, one of them reaching 5.3 on the Richter scale.
Seismometer.png
Figure 2 Measurements of the P and S waves recorded from the earthquake at Keele University
(http://hypocentral.com/blog/2009/04/15/central-italy-earthquake-april-6-2009/)

Destruction:

The earthquake killed at least 287 people, injured at least 1,000, left 40 thousand without homes and destroyed approximately 10 thousand buildings. The town of L'Aquila, which is located about 95 kilometers (60 miles) north-east of Rome was previously hit by another tragic earthquake in 1703. The central Apennine region has also experienced activity in that more recent past like that of a 6.0 magnitude earthquake in 1997 in the town of Umbria. Seismic activity is common in Italy, but not of this great of magnitude. The aftermath of the April 2009 earthquake left the streets of the historic town covered with rubble and objects, like cars, were crushed under fallen buildings. This is shown in Figure 3. Some of the damage to the city can be seen in an aerial view of the city. This can be viewed in Figure 4. Because many of the homes and buildings are constructed with stone and mortar, they are heavy and powerful when they collapse, which basically crunches everything in its path.
car_crushed.jpg
Figure 3 Depicts the destruction caused by the earthquake; a car crushed by debris.
(http://www.silive.com/news/index.ssf/2009/04/by_marta_falconi_associated_pr.html)

ariel_2.jpg
Figure 4 An aerial view of the destruction from the tremors.
(http://cricketdiane.wordpress.com/2009/04/08/)

Consequences and Effects on Nearby People:

Some people described the destruction as "...disaster never before seen,” said Franco Totani and a man named Gianfranco Fini said “Some towns in the area have been virtually destroyed in their entirety”. An American missionary told CNN that the quake "sounded as if a 747 was actually coming in to land". L'Aquila lost many of its historic buildings and landmarks, which now exist buried in the rubble. The hospital in L'Aquila was forced to evacuate for safety hazards. In the small town of Onna, one of the hardest hit villages, 37 of the 400 person population lost their lives. That is nearly 10%.

Was this earthquake predicted?


Weeks before the earthquake hit, a warning was posted on the internet by a technician at Gran Sasso National Laboratory in Abruzzi, Italy. The technician's name is Giampaolo Giuliani. His prediction said that "a massive earthquake would strike based on measurements of radon emissions". Because they were worried about the panic this 'prediction' would cause, Italian officials took Giuliani to court and ignored the serious precautions and warnings. Some people said the following about the claims:

"I am skeptical of the claim," says Shawn Larsen, a geophysicist at Lawrence Livermore National Laboratory in California. "Radon has been claimed to be a precursor of earthquakes for some time, since the late 70s. However, there has been no concrete evidence that it is indeed a predictor of earthquakes."

"It has too many false positives to be useful," says John Rundle,director of the California Institute for Hazard Research, a joint program between different University of California (U.C.) schools "We actually do forecasting but we do that using probabilities. We can't say that an earthquake is going to happen at this point in time and space."

According to Larsen and Rundle, and common scientific knowledge, it is impossible to predict the happening of an earthquake, therefore, Giuliani's 'prediction' was probably just a 'lucky guess'.

Some researchers claim that the release of the gas radon has resulted in many false alarms. This gas has been connected to many seismic occurrences, including earthquakes which are known to release ground gases. But as John Rundle, director of the California Institute for Hazard Research, discusses, other natural phenomena such as rainfall and atmospheric pressure changes also discharge ground gases such as Radon (Fox). Hence, it cannot be accurately used to successfull predict earthquakes.

Conclusion


In conclusion, The L'Aquila earthquake was a devastating disaster in April 2009. The earthquake killed and injured many people and left the city buried under rubble. Though warnings were made public on the internet by a local technician, no accurate prediction could have been issued.

Sources:


"Did a Technician Accurately Forecast the L'Aquila Earthquake--Or Was It a Lucky Guess?: Scientific American." Science News, Articles and Information | Scientific American. Web. 30 Nov. 2009. <http://www.scientificamerican.com/article.cfm?id=radon-earthquake-prediction>.

Donadio, Rachel, and Elisabetta Povoledo. "Italians Comb Through Rubble After Quake." New York Times. New York Times, 6 Apr. 2009. Web. 4 Nov. 2009. <http://www.nytimes.com/2009/04/07/world/europe/07italy.html>.

"Historic L'Aquila reels from quake." BBC News. BBC, 6 Apr. 2009. Web. 4 Nov. 2009. <http://news.bbc.co.uk/2/hi/europe/7986078.stm>.

"L'Aquila earthquake: Fault lines leave Italy prone to tremors - Telegraph." Telegraph.co.uk: news, business, sport, the Daily Telegraph newspaper, Sunday Telegraph - Telegraph. Web. 30 Nov. 2009. <http://www.telegraph.co.uk/news/worldnews/europe/italy/5113465/LAquila-earthquake-Fault-lines-leave-Italy-prone-to-tremors.html>.

"Magnitude 6.3 - CENTRAL ITALY." Usgs. Usgs. Web. 4 Nov. 2009. <http://earthquake.usgs.gov/eqcenter/eqinthenews/2009/us2009fcaf/#details>.

Stimpson, Ian G. "Central Italy Earthquake April 6, 2009." Hypo-theses. Keele University, 15 Apr. 2009. Web. 4 Nov. 2009.

Fox, Stuart. “Did a Technician Accurately Forecast the L'Aquila Earthquake--Or Was It a Lucky Guess?” Scientific American. 7 Apr. 2009. 03 Dec. 2009. <http://www.scientificamerican.com/article.cfm?id=radon-earthquake-prediction>.