GEOLOGISTS WORKING IN Saudi Arabia have found that a series of earthquakes which occurred in the northwest of the country last year were caused by renewed volcanic activity in the region.

Although geologists believed the area was relatively quiet, the Al Madinah province has recently been plagued with earthquakes. Between April and June 2009, more than 30,000 earthquakes struck an ancient lava field there named Harrat Lunayyir – 19 of which hit a magnitude 4 or greater, ABC news reports.

In May of that year, a 5.4 quake occurred, which cracked the town walls of nearby Al Ays, and authorities evacuated 40,000 residents when sensors indicated a volcanic eruption was possible.

Geologists conducting research for the US Geological Survey found that the series of quakes opened a 5-mile long rift, which has allowed magma to rise to just under the surface and could lead to the formation of a new volcano.

However, the hazard is said to be low because of the remoteness of the site and the expected type of eruption – a slow-moving lava flow – reports AFP.

Lead resarcher John Pallister of the Volcano Disaster Assistance Programme at the US Geological Survey (USGS) said:

An eruption, at Lunayyir, if it were to occur, would pose little hazard due to the type of volcanism expected at the site and the remoteness of the vent areas.

There (is) a low probability of large damaging earthquakes related to this type of activity. However, urban development is encroaching on other areas in Saudi Arabia where an eruption would be more serious.