Yesterday afternoon, two moderate earthquakes struck southeast Spain in less than two hours, shaking the popular tourist region of Murcia.
According to the United States Geological Survey (USGS), the first earthquake, measuring a magnitude of 4.5, struck at 5:05 p.m. (UTC) local time and was followed by a magnitude 5.1 mainshock in the same location almost two hours later, at 6:47 p.m. (1647 UTC). While the magnitude reported by the European Mediterranean Seismological Centre (EMSC) for the mainshock agreed with the USGS estimate, the British Geological Survey reported a magnitude of 5.2. Both events had shallow focal depths, which undoubtedly exacerbated the damage.
“Much of the southern Iberian Peninsula is located near the boundary separating the Eurasian and African Plates,” explained Dr. John Alarcon, senior associate at AIR Worldwide. “Within the Peninsula, the collision of these plates is absorbed by crustal faults that are widely distributed in the region but whose slip rates are very low and hence require a long time to accumulate energy that is translated into earthquakes. Because of these slow slip rates, these faults are very difficult to be fully characterized based on past recorded events and/or geomorphology studies.” One such fault is the Alhama de Murcia fault (on the Southeastern Beltic Cordillera), on which the current events may have occurred, though further study is required as to determine this with accuracy.
The epicenters of yesterday’s earthquakes were located about 3.5 km northeast of the farming town of Lorca. The historic center of the town was particularly hard hit. Local authorities report damage to more than 80% of buildings in the town, and many of the historical and cultural buildings sustained heavy damage.
Many of the historic buildings in Lorca date from the sixteenth century. “These unreinforced masonry structures have a limited ability to resist earthquake lateral loads without cracking or suffering wall collapse,” said Dr. Alarcon. “Modern construction in the region must adhere to a strict building code introduced by the central Spanish government in 2006.” The “Código Técnico de la Edificación” or CTE was developed over a period of seven years following the passing of Law 38 of the 1999 building act, designed to unify building regulation throughout Spain under a single code covering all hazards, including seismic hazard.
According to AIR, natural catastrophe insurance in Spain is mandatory for all fire, motor, rail and other property damage policies though it is rare for primary insurers to provide this cover themselves. The “Consorcio de Compensacion de Seguros” is a state-guaranteed insurance company that covers all direct physical losses from natural events deemed “abnormal” by the government. The premium written by the Consorcio comes in the form of a government tax on certain designated classes of insurance, which is paid by the insurer. Business interruption is covered in the event that losses “represent an alteration of the normal results of the economic activity of the insured party and derive from the stoppage, suspension, or reduction of productive processes or the business of said activity.” The Consorcio does not, however, cover agricultural property, or construction and erection risks.
While damage appears to be concentrated in Lorca and Totana (20 km to the northeast), there have been reports of damage in other nearby towns and villages, including Albacete and Velez-Rubio in Almeria.
The current events are the deadliest to strike the area since 1956, when an earthquake toppled buildings and killed 12 people in Albolote, a town in the southern province of Granada.
Source : AIR Worldwide Press Release
