The Harrat Khaybar volcanic field in Saudi Arabia. Image courtesy of NASA, taken in 2008.
Now, I might take this report with a Volvo-sized grain of salt, but I've seen a few reports lately of an earthquake swarm going on in Saudi Arabia, near the Harrat Ash-Shaqqah in Al-Eis region (apparently near Madina, but I'm not 100% sure). I might normally just chalk this up to the tectonics of the Arabian Plate, however, the latest article I read this morning, Saleh Al-Muhawis, Director General of the Civil Defense in Madina Region mentioned this as the cause of the seismicity:
... magma (molten rocks below the surface) was pushed by some force from a depth of 8 km to a depth of 4 km below the surface.
UPDATE 5/14/2009, 4:15 PM Pacific: Some more details about the earthquake swarms. A so-called expect, the Director of the Center for Remote Sensing at Boston Univ., claims it is just "movement along a fault" ... which, of course, is different than what the Saudi officials have said. Just shows what happens when the press talks to "experts".
You can imagine why that caught my attention. How the Director General knows this is not mentioned - and honestly, I can't think of a way that they could be sure of this right now. That being said, volcanism is not something new to Saudi Arabia, in fact, the area around Medina does have volcanoes that have erupted historically, some as recently as 1810. Saudi Arabia is located along two spreading centers - along the Gulf of Aden and in the Red Sea, and in recent years we saw some impressive volcanism in the Red Sea off Yemen. Most of the volcanism takes the form of basaltic cinder cones, tuff cones and lava fields (see image above) that might not have a dramatic effect on anywhere but the region directly surround the volcano - something like Paricutin in Mexico.
Could this be the start off another cinder cone or lava field in western Saudi Arabia? Right now, I'd say we have far too little information to make any such suggestions, however, if the earthquake swarm increases and seem to follow the pattern of magma moving upwards, it might be a different story.
Any of you Eruptions seismo-heads want to see what you can dig up?