Earthquake off Algeria in 2003

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Epicenter of the earthquake

The 2003 earthquake off Algeria , also known as the Boumerdès earthquake , was an earthquake in the Mediterranean Sea on May 21, 2003 off the coast of Algeria , killing 2,266 people. A tsunami (“tidal wave”, literally “harbor wave”) occurred that reached the Balearic Islands and caused property damage there.

Course and cause

On May 21, 2003, at 18:44 UTC (19:44 CET ) , an earthquake with a magnitude of M w 6.8 occurred in the sea around 20 km northeast of Boumerdès , the capital of the province of Boumerdès . The depth of the hypocenter was determined to be twelve kilometers.

The focus of the earthquake lies in the border region between the European and African plates . The African plate moves here at a speed of 6 mm per year to the northwest against the European plate. Earthquakes are common and are caused by side- shift and thrust movement . The hearth surface solution revealed that the earthquake was caused by excessive movements.

Immediate damage

Damage in the Algerian city of Boumerdes

The seismic surges caused over 1,000 buildings to collapse in the country's coastal regions. In total, more than 40,000 houses were damaged and around 150,000 people were left homeless. The earthquake claimed 2,266 lives and injured more than 10,000 people. The infrastructure of the Algiers -Boumerdès- Réghaïa - Thénia region was badly damaged, and subsea cables off the coast were disrupted by submarine slides . The damage was about 100 million US dollars , other estimates range from 600 million to 5 billion dollars.

Tsunami

Port of Palma de Mallorca, which was flooded

The shock waves triggered a tsunami that passed through the Mediterranean at 300 km / h . 54 minutes later, at 8.45 p.m., the water receded up to 150 meters on the coasts of the Balearic Archipelago, which is about 272 kilometers from the epicenter . Shortly afterwards, two successive waves about two meters high rolled in and flooded the beaches and some beach roads. A tsunami wave was also observed on the Spanish coast of Alicante , Castellon and Murcia .

The quake off Algeria was not very strong, which meant that not too much energy could be transferred to the tsunami. So he only reached a small height. Nevertheless, on Mallorca (in Palma ) and Ibiza (here especially in the port city of Santa Eulària ) around 200 boats, some fishermen's huts and dozens of cars were destroyed or washed away. People were not harmed because the Oceanographic Institute of Palma de Mallorca had determined the sea level fluctuation before the wave hit and issued a warning.

Consequences

Although this was not the first tsunami in the Mediterranean (the Messina earthquake had triggered a much more devastating tidal wave as early as 1908 ), after the incident became known, a public discussion began about protective measures and early warning systems for the Mediterranean , which is a highly earthquake-prone zone. Because in the Mediterranean there is very little time for a warning and subsequent evacuation. While the tsunamis in the Pacific sometimes take over seven hours to migrate across the ocean, in the Mediterranean they can hit the opposite coast within 30 minutes.

Web links

Individual evidence

  1. ^ G. Dan, N. Sultan, B. Savoye, J. Déverchère, K. Yelles: Quantifying the role of sandy-silty sediments in generating slope failures during earthquakes: examples from the Algerian margin . In: International Journal of Earth Sciences . tape 98 , no. 4 , 2009, p. 769-789 .
  2. ↑ a b Magnitude 6.8 Northern Algeria. United States Geological Survey , accessed December 25, 2019 .
  3. ↑ a b c Significant Earthquake. NOAA , accessed January 9, 2010 .

Coordinates: 36 ° 57 '50.4 "  N , 3 ° 38' 2.4"  E