Antaletriangle
03-12-2009, 11:37 AM
http://www.news.com.au/heraldsun/story/0,21985,25157018-662,00.html
AUSTRALIA - Seismologists are at a loss to explain the flurry of earthquakes that have hit a small Wheatbelt town. Beacon, 320km north-west of Perth, has had roughly 100 earthquakes in the last month. The largest, which registered nearly five on the Richter Scale came within 24 hours of earthquakes in Melbourne and off the coast near Broome on Friday. The earthquake clusters, known as swarms, were not unusual for the wheatbelt area but what was UNUSUAL was the migration of the swarms around the wheatbelt. Similar patterns were noted in Koorda in 2003 to 2005 and Burrakin between 2000 and 2002. "These ones like the Beacon case where you seem to get several moderate earthquakes and then lots and lots of smaller quakes, it is a bit unusual. It's called a swarm because it doesn't follow the typical foreshock, minishock, aftershock pattern or at least it doesn't seem to. That's this migrating swarm, I'm not sure I've ever heard of that before. For that area it would seem that this behaviour is not atypical." Seismologists were uncertain if the swarms were related to larger earthquake events such as the wheatbelt's Meckering earthquake in 1968, which registered 6.8 on the Richter scale. The seismic activity could be relieving stresses and avoiding larger earthquakes or it could result in a big rupture. "They seem to die out gradually, we don't really know that much of what to expect, I mean Burrakin went on for a couple of years, Koorda sort of gradually started up and faded out. It could continue for a while."
Korumburra earthquake BIGGEST FOR 36 YEARS - Scientists have moved to calm nerves after the biggest earthquake to rattle Melbourne in 36 years. Friday night's rumble measured 4.6 on the Richter scale.
AUSTRALIA - Seismologists are at a loss to explain the flurry of earthquakes that have hit a small Wheatbelt town. Beacon, 320km north-west of Perth, has had roughly 100 earthquakes in the last month. The largest, which registered nearly five on the Richter Scale came within 24 hours of earthquakes in Melbourne and off the coast near Broome on Friday. The earthquake clusters, known as swarms, were not unusual for the wheatbelt area but what was UNUSUAL was the migration of the swarms around the wheatbelt. Similar patterns were noted in Koorda in 2003 to 2005 and Burrakin between 2000 and 2002. "These ones like the Beacon case where you seem to get several moderate earthquakes and then lots and lots of smaller quakes, it is a bit unusual. It's called a swarm because it doesn't follow the typical foreshock, minishock, aftershock pattern or at least it doesn't seem to. That's this migrating swarm, I'm not sure I've ever heard of that before. For that area it would seem that this behaviour is not atypical." Seismologists were uncertain if the swarms were related to larger earthquake events such as the wheatbelt's Meckering earthquake in 1968, which registered 6.8 on the Richter scale. The seismic activity could be relieving stresses and avoiding larger earthquakes or it could result in a big rupture. "They seem to die out gradually, we don't really know that much of what to expect, I mean Burrakin went on for a couple of years, Koorda sort of gradually started up and faded out. It could continue for a while."
Korumburra earthquake BIGGEST FOR 36 YEARS - Scientists have moved to calm nerves after the biggest earthquake to rattle Melbourne in 36 years. Friday night's rumble measured 4.6 on the Richter scale.