Earthquakes in the Canberra Region - Geoscience Australia
Earthquakes in the Canberra Region - Geoscience Australia
Earthquakes in the Canberra Region - Geoscience Australia
- No tags were found...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>Earthquakes</strong> <strong>in</strong> <strong>the</strong> <strong>Canberra</strong> <strong>Region</strong>actually heard a series of three bangs <strong>in</strong> quick succession with <strong>the</strong> first be<strong>in</strong>g <strong>the</strong> loudest.Two to 3 km south of <strong>the</strong> epicentre, it was experienced as "a bit of a rumble" which shook<strong>the</strong> house. N<strong>in</strong>e to 10 km SSW of <strong>the</strong> epicentre, a woman play<strong>in</strong>g <strong>the</strong> piano felt itmomentarily and said it sounded like a loud truck and wall beams creaked. Thirteen to 14km ESE of <strong>the</strong> epicentre, <strong>the</strong> earthquake was reported felt like a big explosion. There wasa loud noise and a shake with only <strong>the</strong> fly screens rattl<strong>in</strong>g a bit.It is important to note that uncerta<strong>in</strong>ties <strong>in</strong> earthquake locations <strong>in</strong> <strong>the</strong> <strong>Canberra</strong> region canbe as large as 5 km or more. This makes it difficult to ascerta<strong>in</strong> if an earthquake isassociated with a particular fault. Consequently, it is uncerta<strong>in</strong> whe<strong>the</strong>r <strong>the</strong> Lake GeorgeFault is still active, but it appears likely.Figure 14. Lake George. The escarpment, at <strong>the</strong> left of <strong>the</strong> picture, has wea<strong>the</strong>red backfrom its orig<strong>in</strong>al position on <strong>the</strong> Lake George Fault which is to <strong>the</strong> right of <strong>the</strong> highway.This has occurred by erosion and landslides, like this one <strong>in</strong> June 2005 (<strong>in</strong>set) whichcaused a semi trailer to jack knife.MURRUMBATEMAN EARTHQUAKESThe cluster of earthquake epicentres at <strong>the</strong> northwest corner of Figure 2 is just south of <strong>the</strong>township of Murrumbateman, 35 km NNW of <strong>the</strong> <strong>Canberra</strong> GPO.Fourteen earthquakes, with Richter magnitudes rang<strong>in</strong>g from 1.2-2.4 have occurred with<strong>in</strong>a square with sides 10 km from <strong>the</strong> township dur<strong>in</strong>g <strong>the</strong> period 1981-1995. Of <strong>the</strong>seevents, n<strong>in</strong>e were ma<strong>in</strong> shocks (an average of 0.6 per year), and five of <strong>the</strong>se were <strong>in</strong> <strong>the</strong>area of Figure 2.20