Queensland (Kilkivan) earthquake: initial insurance outlook, historical context and Newcastle 1989 comparison
Southeast Queensland experienced an unusual moderate earthquake on Saturday 16 August 2025 at 9:49 am AEST. Geoscience Australia (GA) places the event near Kilkivan (Gympie Region), and characterises it as magnitude 5.6 at ~10 km depth; tremors were widely felt from the Fraser Coast through Brisbane and into northern NSW, with more than sixteen thousand felt reports lodged. Newsrooms and authorities noted temporary power outages to roughly 13,000–14,000 properties across the South Burnett and Fraser Coast, disruptions to public transport, and scattered instances of minor -non-structural- damage (e.g., dislodged ceiling panels, cracked plaster, toppled contents). Crucially, early coverage and official statements reported no serious injuries and no major structural damage. (Geoscience Australia, ABC, The Guardian, Courier Mail)
Why are different magnitudes being quoted:
GA’s rapid product lists M 5.6, whereas international agencies report a smaller event: the USGS solution is M 4.9 (Mw) located ~20 km ENE of Booie (near Kingaroy) and EMSC likewise reports M 4.9 at 1 km depth. This is not a contradiction so much as a difference in magnitude scales and data. GA’s operational magnitude for Australian events is typically a local magnitude (ML/MLv) derived from nearfield, -higher frequency recordings on the national network, while USGS/EMSC publish moment magnitude (Mw) from -long period, tele seismic waves, which maps directly to seismic moment and is preferred for global comparisons and catastrophe modelling. A numerical gap of 0.7 magnitude units (5.6 vs 4.9) corresponds to roughly an- ~11× difference in radiated energy under the standard USGS relation, which is precisely why ML and Mw should not be mixed without context when benchmarking events. Depth was also reported inconsistently in early media (some outlets quoted 2 km), but GA/USGS/EMSC solutions converge near ~10 km. (Geoscience Australia, Earthquake Track, EMSC, USGS, USGS, 9News)
Historical context near the Kilkivan epicentral corridor:
Although Queensland is one of Australia’s least seismically active states, the broader Burnett–Mary–Gladstone belt has produced several significant historical earthquakes. Notable pre-instrumental and -early-instrumental events include Gayndah 1883 (ML 5.9), Mundubbera 1910 (ML 5.2), and Gayndah 1935 (ML 6.1), all documented in University of Queensland and GA catalogues. The largest event relevant to the region’s hazard—long thought to be offshore—has recently been relocated onshore near Camboon-: a re-assessment places the 1918 “Bundaberg/Gladstone” earthquake at Mw ~6.0, with a yearlong inland aftershock trail; Figure 1 shows the location of the Kilkivan earthquake and some major southeast–central Queensland’s historical earthquakes. Offshore, the Bowen 2016 (M 5.8) earthquake -was widely felt but caused limited damage. These histories underline that reactivation of ancient intraplate faults in SEQ can yield moderate events within populated belts. (Seismological Observatory (UQ), eCat (Geoscience Data Catalogue by GA), Inspector-General of Emergency Management (Queensland), Geoscience Australia)
Insurance implications:
With no catastrophe declaration and no published claims data to date, insurers should prepare for a long tail of small claims concentrated in non-structural damage (plasterboard and masonry veneer cracking; tiles; parapets and chimneys where present), contents and minor business interruption due to power losses or precautionary inspections. The risk of a damaging aftershock is low for a mainshock of this size, but not zero; aftershocks are expected to taper over the coming days to weeks.
How does this event compare with the 1989 Newcastle earthquake?
Newcastle remains Australia’s most consequential urban earthquake in the modern era. Geoscience Australia lists the mainshock at ML 5.6 (Mw ≈ 5.4), which resulted in 13 deaths, more than 160 injuries, and a total economic loss of approximately A$4 billion in 1989 values. Insured losses are variously reported as “over A$1 billion” (GA) and around A$862 million (AIDR), reflecting differences in data sources and accounting bases. Despite this range, both confirm that Newcastle was a major insurance catastrophe, with losses driven primarily by the vulnerability of unreinforced masonry (URM) structures and the concentration of exposure in a densely built CBD environment. (Geoscience Australia, AIDR Knowledge Hub)
The scale of this impact is underscored by the Insurance Council of Australia’s recent Catastrophe Resilience Report, which identifies the 1989 Newcastle CBD earthquake as the nation’s third most devastating natural hazard, with a normalised loss of $6.54 billion (Insurance Council of Australia). This places the event among the largest disasters in Australia’s insurance history, highlighting the enduring relevance of earthquake risk to the sector.
By contrast, the Kilkivan earthquake struck a rural/regional setting dominated by timber housing stock, where seismic demand was insufficient to drive widespread structural damage. This divergence illustrates how loss outcomes are shaped not only by magnitude but also by exposure density and building vulnerability characteristics.
Table1: A comparison of Kilkivan 2025 with Newcastle 1989 earthquakes (Sources: Geoscience Australia, ABC, EMSC, Earthquake Track, AIDR Knowledge Hub)
| Attribute | Kilkivan (Queensland) 2025 | Newcastle (NSW) 1989 |
| Reported magnitude & scale | GA: ML 5.6; USGS/EMSC: Mw 4.9 | GA: ML 5.6; Mw ≈ 5.4 |
| Depth (early consensus) | ~10 km (GA 10 km, USGS 10 km, EMSC 1 km) | ~10–12 km |
| Exposure setting | Regional/rural SEQ; lower asset density | Dense urban Newcastle; high asset density |
| Observed effects | Widespread felt shaking; minor, mostly non-structural- damage; ~13–14k outages; no serious injuries reported | 13 deaths, 160+ injured; significant URM damage and partial collapses; widespread disruption |
| Early insured loss- signals | No ICA declaration; no published claims/loss figures as at 18 Aug; losses likely modest | Total loss ~A$4 b; insured loss ~A$0.86–>1 b (1989 AUD) |
| Building stock & code | Predominantly timber; AS 1170.4‑1993 published Aug 1993 and adopted into the BCA in 1994; superseded by AS 1170.4‑2007. | Substantial URM inventory; pre-AS- 1170.4 detailing absent in ordinary construction |
A note on magnitude scales for risk teams:
For Australian portfolio analytics, it is best practice to normalise to Mw (moment magnitude) because it scales with seismic moment and avoids ML saturation and path/site biases. GA’s operational ML is excellent for rapid situational awareness, while Mw offers a more consistent feed for loss modelling and crossevent- benchmarking. Remember the Gutenberg–Richter energy relation (energy ∝ 10^(1.5M)): a +1.0 magnitude step releases ~32× more energy; a +0.7 step implies ~11×—hence the importance of comparing apples with apples (USGS). Figure 2, illustrates this concept by plotting the relative energy of the Newcastle earthquake (Mw 5.6) and a hypothetical Mw 6.0 earthquake, in comparison to the recent Queensland (Kilkivan) earthquake (Mw 4.9).
Bottom line for insurers & reinsurers:
All available indicators point to a contained, low-severity insurance event in Queensland. This is not Newcastle 1989; it is, however, a salient reminder that SEQ’s intraplate faults can produce moderate events within reach of population centres. Use the episode to stress check- URM exposure controls in regional town centres and verify non-structural restraint requirements in risk engineering- programs. (The Guardian, Insurance Council of Australia)
References:
Geoscience Australia. “Earthquake information for media outlets: Recent earthquake 16 August 2025: M 5.6 Kilkivan, QLD.” https://www.ga.gov.au/news/earthquake-information-for-media-outlets Geoscience Australia
ABC News. “Magnitude-5.6 earthquake felt north of Brisbane.” https://www.abc.net.au/news/2025-08-16/qld-earthquake-murgon-sunshine-coast-risbane-geoscience-aus/105662170 ABC
The Guardian. “Aftershocks expected after south-east Queensland shaken by 5.6-magnitude earthquake.” https://www.theguardian.com/australia-news/2025/aug/16/south-east-queensland-shaken-by-earthquake-kilkivan-brisbane The Guardian
The Courier Mail. “From the earthquake epicentre: Kilkivan residents on moment Mag 5.6 hit.” https://www.couriermail.com.au/news/queensland/from-the-earthquake-epicentre-kilkivan-residents-on-moment-mag-56-hit/news-story/7195ad7065a734bfdefe533170e9e30d The Courier-Mail
9News. “Regional Queensland struck by 5.6 magnitude earthquake.” https://www.9news.com.au/national/regional-queensland-struck-by-56-magnitude-earthquake/7ba75a0d-0418-4c76-a6f4-314e4686ec4d 9news.com.au
USGS Earthquake Hazards Program. “M 4.9 — 20 km ENE of Booie, Australia (event page).” https://earthquake.usgs.gov/earthquakes/eventpage/us6000r1j3/dyfi USGS
EMSC. “NEAR EAST COAST OF AUSTRALIA — M 4.9, depth 10 km (2025-08-15 23:49:24 UTC).” https://www.emsc-csem.org/Earthquake_information/earthquake.php?id=1849005 EMSC
EarthquakeTrack. “4.9 magnitude earthquake near Wondai/Booie, Queensland (2025-08-15 23:49:24 UTC).” https://earthquaketrack.com/quakes/2025-08-15-23-49-24-utc-4-9-10 Earthquake Track
University of Queensland — UQ Seismological Observatory. “Earthquake information for Gladstone region (historical list incl. Gayndah 1883; Mundubbera 1910; Gayndah 1935).” https://www.quakes.uq.edu.au/quakeinfo-gladstone.html UQ Seismological Observatory
Geoscience Australia (eCat). “Resolving the location and magnitude of the 1918 Queensland (Bundaberg) Earthquake, Australia.” https://ecat.ga.gov.au/geonetwork/srv/api/records/df80936d-6517-4214-95f3-ae0726857424 eCat
IGEM Queensland. “Reassessment of 1918 Queensland earthquake (Camboon relocation, Mw ~6.0–6.2).” https://www.igem.qld.gov.au/research/case-studies/reassessment-1918-queensland-earthquake IGEM
Geoscience Australia. “Magnitude 5.8 earthquake shakes far north Queensland (Bowen, 18 Aug 2016).” https://www.ga.gov.au/news/news-archive/magnitude-5.8-earthquake-shakes-far-north-queensland Geoscience Australia
Geoscience Australia. “Newcastle Earthquake (1989) — factsheet.” https://www.ga.gov.au/bigobj/GA10000.pdf Geoscience Australia
AIDR Knowledge Hub. “Newcastle earthquake, NSW 1989.” https://knowledge.aidr.org.au/resources/earthquake-newcastle-1989/ AIDR Knowledge Hub
Insurance Council of Australia. (2023). Insurance Catastrophe Resilience Report. https://insurancecouncil.com.au/wp-content/uploads/2023/09/20897_ICA_Cat-Report_Print-2023_RGB_Final_Spreads.pdf Insurance Council of Australia
USGS. “Magnitude Types.” https://www.usgs.gov/programs/earthquake-hazards/magnitude-types USGS
USGS. “Earthquake Magnitude, Energy Release, and Shaking Intensity.” https://www.usgs.gov/programs/earthquake-hazards/earthquake-magnitude-energy-release-and-shaking-intensity USGS
USGS. “How Much Bigger…? Calculator (magnitude vs energy/amplitude).” https://earthquake.usgs.gov/education/calculator.php USGS
Earthquakes@GA (event data hub). https://earthquakes.ga.gov.au/
