The Dalton-Gunning Zone, only 60 km north of Canberra, has been assessed as one of the highest hazard earthquake areas in eastern Australia. Three earthquakes with Richter magnitudes of 5.5 or greater are known to have occurred, during the last 130 years, in November 1886, November 1934 and March 1949. All three were felt strongly in the Canberra area.
The 1886 event caused damage in Yass and was felt in Queanbeyan. The magnitude of 5.5 was deduced from the radius over which the shock was felt as there were no seismographs to record it at the time.
In the 1934 earthquake, practically every brick and stone building in Gunning was damaged and the event was felt over much of SE New South Wales. The earthquake was the culmination of a week-long series of foreshocks and was reported to be the worst shock in the history of Gunning. It was followed by a long series of aftershocks which were felt strongly as far as Cooma, 160 km away.
The epicentre of the 1934 earthquake was south of Dalton at S34° 48.000 E149° 12.000.
In Canberra, trees vibrated violently, a road appeared to be undulating, and the water in the swimming pool at Manuka was shaken, as was the telephone in the pool office. It wobbled so much that it began ringing. The magnitude of the earthquake was ML 5.6, the same as that of the December 1989 Newcastle event.
The 1949 earthquake (magnitude ML 5.5) was felt from Sydney and Katoomba in the north to Jindabyne, Cooma and Narooma in the south (Everingham and others, 1982).
According to The Sun newspaper (Sydney) of 11 March 1949, the worst damage was in the Dalton area where ``buildings swayed crazily, walls cracked, chimneys toppled, water tanks burst, and more than 100 bottles of liquor in an hotel were smashed. In Canberra, minor cracks were reported in the walls of some houses, and doors burst open. A number of cracks have appeared in walls of the Government administrative block near Parliament House. A lift stopped working''.
The 1984 Oolong earthquake struck at 4:30pm on 9 August causing extensive cracking in a brick homestead at Oolong and the Anglican Church in Dalton, both of which had suffered previous damage during the 1949 earthquake. It was felt over a radius of about 70 km. The epicentral intensity was relatively high because the earthquake was very shallow.
The epicentre of the 1984 Oolong earthquake was also south of Dalton at S34° 48.600 E149° 10.200.
At the listed coordinates you will find St Matthew’s Anglican Church 1878. According to the NSW heritage listing, the church is “highly significant locally for its religious and cultural value to the community. The stone building featuring rendered quoins and Gothic arched windows and bell tower, is notable in the historical landscape of the area”. Interestingly, no mention is made of the impact of earthquakes on it over the years.
Logging requirements
To claim this Earthcache you will have to visit the listed coordinates and collect the answers to 5 questions and email these to us for verification using the contact details in the listing. Once verified, you can post your log. We will respond as quickly as we can.
Optional: we also ask that you post a picture of yourself or your team in the area but please don’t give any of the answers away!
Here are the questions for you to answer:
- How far is it from the church to the epicentre of the 1984 earthquake?
- On the south eastern corner a buttress has come away from the main structure. What is the approximate “gap” at the top on its north side?
- Look at the church for further evidence of earthquake damage. Identify another area of damage and how it has been repaired?
- Steps have been taken to help the structure withstand future earthquakes. Can you identify one of these?
- The church has been constructed using a range of local stone. On the western wall of the original church you will see dark stones. What colour are the crystals in these stones?
Good luck and enjoy your visit to the Dalton-Gunning earthquake zone!
For more information:
https://www.ga.gov.au and search for “Earthquakes in the Canberra Region”
McCue, K., Kennett, B.L.N., Gaull, B.A., Michael-Leiba, M.O., Weekes, J. & Krayshek,C., 1989 - A century of earthquakes in the Dalton-Gunning region of New South Wales. BMR Journal of Australian Geology & Geophysics, 11, 1-9.