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The Papua New Guinea (PNG) region has been formed within an oblique convergence zone between the north-northeasterly moving Australian plate and the Pacific plate. The region is subject to most types of tectonic activity, including active folding, faulting and volcanic eruptions and hence is arguably one of the most seismically active regions in the world. Given its high level of seismic activity, PNG would benefit from a dense monitoring network to enhance the efficiency of the earthquake emergency response operations. A program to densify the earthquake monitoring network of PNG by utilizing low-cost sensors has been developed by Geoscience Australia in collaboration with the Department of Mineral Policy and Geohazards Management in PNG. To verify the performance, trial low-cost sensors were co-located with observatory-quality instrumentation for a period of one month in Port Moresby and Rabaul observatories. The comparisons demonstrated comparable recording results across a wide seismic frequency range. Once this proved successful, the first deployments were undertaken recently, with sensors installed in the Bialla International School, Kimbe International School and the Earth Science Division of the University of PNG. Educational institutions are ideal for the installation of these sensors as they can provide guaranteed internet and electricity, allowing for continuous monitoring of earthquakes. The data acquired by these stations will feed into the existing networks for national earthquake and volcano monitoring, thus expanding the national seismic network of PNG. This work is being undertaken as part of the Australian Aid program. Presented at the 2020 Seismological Society of America (SSA) Annual Meeting

Through Australian Department of Foreign Affairs and Trade, Geoscience Australia has been working closely with the Government of Papua New Guinea technical agencies (Rabaul Volcano Observatory, Port Moresby Geophysical Observatory, and Engineering Geology Branch) since September 2010 to enhance their capabilities to monitor and assess natural hazards. The objective of this program is to support the Government of Papua New Guinea in developing fundamental information and practices for the effective response and management of natural hazard events in PNG. Earthquakes as natural hazards are one of the key focus points of this project, as they continue to cause loss of life and widespread damage to buildings and infrastructure in Papua New Guinea. The country’s vulnerability to earthquakes is evident from the significant socio-economic consequences of recent major events in Papua New Guinea, e.g., a magnitude 7.5 earthquake that occurred in the Hela Province of Papua New Guinea in 2018. Earthquake risk is likely to increase significantly in the years to come due to the growth in population and urbanization in Papua New Guinea. However, earthquake risk, unlike hazard, can be managed and minimized. One obvious example would be minimizing earthquake risk by constructing earthquake-resistant structures following building standards. The high level of earthquake hazard of Papua New Guinea has been long recognised and the suite of building standards released in 1982 contained provisions to impart adequate resilience to buildings based on the best understanding of seismic hazard available at that time. However, the building standards and incorporated seismic hazard assessment for Papua New Guinea has not been updated since the 1980s. The integration of modern national seismic hazard models into national building codes and practices provides the most effective way that we can reduce human casualties and economic losses from future earthquakes. This report aims at partially fulfilling this task by performing a probabilistic seismic hazard assessment to underpin a revision of the earthquake loading component of the building standards of Papua New Guinea. The updated assessment offers many important advances over its predecessor. It is based on a modern probabilistic hazard framework and considers an earthquake catalogue augmented with an additional four decades-worth of data. The revised assessment considers advances in ground-motion modelling through the use of multiple ground-motion models. Also, for the first time, the individual fault sources representing active major and microplate boundaries are implemented in the input hazard model. Furthermore, the intraslab sources are represented realistically by using the continuous slab volume to constrain the finite ruptures of such events. This would better constrain the expected levels of ground motion at any given site in Papua New Guinea. The results suggest a high level of hazard in the coastal areas of the Huon Peninsula and the New Britain–Bougainville region, and a relatively low level of hazard in the southern part of the New Guinea Highlands Block. In comparison with the seismic zonation map in the current design standard, it can be noted that the spatial distribution used for building design does not match the bedrock hazard distribution of this study. In particular, the high seismic hazard of the Huon Peninsula in the revised assessment is not captured in the current seismic zoning map, leading to a significant under-estimation of hazard in PNG’s second-largest city, Lae. It can also be shown that in many other regions and community localities in PNG the hazard is higher than that regulated for the design of buildings having a range of natural periods. Thus, the need for an updated hazard map for building design has been confirmed from the results of this study, and a revised map is developed for consideration in a revised building standard of Papua New Guinea.

Papua New Guinea (PNG) lies in a belt of intense tectonic activity that experiences high levels of seismicity. Although this seismicity poses significant risks to society, the Building Code of PNG and its underpinning seismic loading requirements have not been revised since 1982. This study aims to partially address this gap by updating the seismic zoning map on which the earthquake loading component of the building code is based. We performed a new probabilistic seismic hazard assessment for PNG using the OpenQuake software developed by the Global Earthquake Model Foundation (Pagani et al. 2014). Among other enhancements, for the first time together with background sources, individual fault sources are implemented to represent active major and microplate boundaries in the region to better constrain the earthquake-rate and seismic-source models. The seismic-source model also models intraslab, Wadati–Benioff zone seismicity in a more realistic way using a continuous slab volume to constrain the finite ruptures of such events. The results suggest a high level of hazard in the coastal areas of the Huon Peninsula and the New Britain – Bougainville region, and a relatively low level of hazard in the southwestern part of mainland PNG. In comparison with the seismic zonation map in the current design standard, it can be noted that the spatial distribution of seismic hazard used for building design does not match the bedrock hazard distribution of this study. In particular, the high seismic hazard of the Huon Peninsula in the revised assessment is not captured in the current building code of PNG. <b>Citation:</b> Ghasemi, H., Cummins, P., Weatherill, G. <i>et al.</i> Seismotectonic model and probabilistic seismic hazard assessment for Papua New Guinea. <i>Bull Earthquake Eng, </i><b>18</b>, 6571–6605 (2020). https://doi.org/10.1007/s10518-020-00966-1

Hot emissions of mainly sulphur dioxide and carbon dioxide took place from a mound in Koranga open cut, near Wau, following a landslide at the end of May, 1967. Rocks of the Holocene volcano, Koranga, are exposed in the open cut. The emissions lasted about three months, and ceased on 13 August after another landslide removed the active mound. During the period of activity, recorded temperatures ranged up to 680°C; no anomalous seismic or tilt phenomena were recorded. The cause of the activity is not known, but it is thought that the high temperatures and gases may have been the result of the spontaneous combustion of reactive sulphides and carbonaceous material present in the altered rocks of Koranga volcano.

<div>The Ramu-Markham Fault (RMF) runs along the northern edge of the Markham Valley in eastern Papua New Guinea’s Morobe Province. It is the active plate boundary between the South Bismarck Plate and&nbsp;the New Guinea Highlands/Papuan Peninsula Blocks, and is thought to accommodate about 4 cm/yr of convergence associated with the Finisterre arc-continent collision. Because Papua New Guinea’s recently published national seismic hazard map revealed a potential vulnerability of its 2nd largest city, Lae, to RMF earthquakes, Lae has become the focus of a seismic risk study. One of the aims of this study is to improve the characterisation of the earthquake potential along the RMF, and for this reason a new Global Navigation Satellite System (GNSS) campaign has been undertaken to re-survey over 70 existing benchmarks in and around Morobe Province, including about 35 benchmarks in and around the city of Lae itself. The vast majority of these benchmarks have now been surveyed, and in this paper we discuss the survey and a preliminary analysis of the data.</div><div><br></div>Presented at the 2023 Australian Earthquake Engineering Society (AEES) Conference

Papua New Guinea (PNG) is situated at the edge of the Pacific “ring of fire” and is exposed to frequent large earthquakes and volcanic eruptions. Earthquakes in PNG, such as 2018 Hela Province event (M7.5), continue to cause loss of life and widespread damage to buildings and infrastructure. Given its high seismic hazard, PNG would benefit from a dense seismic monitoring network for rapid (near real-time), as well as long-term, earthquake hazard and risk assessment. Geoscience Australia (GA) is working with technical agencies of PNG Government to deliver a Department of Foreign Affairs and Trade (DFAT) funded technical disaster risk reduction (DRR) program to increase community resilience on the impact of natural hazards and other secondary hazards. As part of this program, this study explores the feasibility of establishing a low-cost, community-based seismic network in PNG by first verifying the performance of the low-cost Raspberry Shake 4D seismograph, which includes a three-component strong-motion MEMs accelerometer and one (vertical) short-period geophone. A Shake device was deployed at the Rabaul Volcanological Observatory (RVO) for a period of one month (May 2018), relaying data in real-time via a 3G modem. To assess the performance of the device, it was co-located with global seismic network-quality instruments that included a three-component broadband seismometer and a strong motion accelerometer operated by GA and RVO, respectively. A key challenge for this study was the rather poor data service by local telecommunication operators as well as frequent power outages which caused repeated data gaps. Despite such issues, the Shake device successfully recorded several earthquakes with magnitudes as low as mb 4.0 at epicentral distances of 600 km, including earthquakes that were not reported by international agencies. The time-frequency domain comparisons of the recorded waveforms with those by the permanent RVO instruments reveal very good agreement in a relatively wide frequency range of 0.1-10 Hz. Based on the estimated noise model of the Shake device (seismic noise as well as instrument noise), we explore the hypothetical performance of the device against typical ground-motion amplitudes for various size earthquakes at different source-to-site distances. Presented at the 2018 Australian Earthquake Engineering Society (AEES) Conference

On 6th July 2006, an intense swarm of earthquake activity began in the Sulu Range, Central New Britain, Papua New Guinea. The earthquakes were felt almost every one to two minutes, 24 hours a day, with modified Mercalli intensities of MM1 to MM4. They were accompanied by unusual vigorous activity in the hot springs southwest of the Sulu Range. Fearing a possible eruption and tsunami, about 1000 locals were evacuated.

In this study, we performed a probabilistic seismic hazard assessment (PSHA) for Papua New Guinea (Figure 1) to underpin a revision of the seismic zoning map for the national building code of PNG (Figure 2). To perform PSHA, we compiled a composite catalogue for the period of 1900-2017 (Figure 3). We then developed magnitude conversion equations to homogenize the catalogue in terms of moment magnitude scale (M_W , Figure 4). In contrast to previous studies in PNG (e.g. Ghasemi et. al, 2016), we developed a seismotectonic model that includes 18 fault models (Figure 5) combined with the distributed seismicity (Figure 6) to model earthquake sources. Following the classical PSHA methodology, we mapped the seismic hazard in terms of peak ground acceleration (PGA) with 10% probability of exceedance in 50 years (Figure 1). We also computed hazard curves (Figure 7) and uniform hazard spectra (Figure 8) at the location of major population centres in PNG (black circles in Figure 1). Results of this study indicate a high level of hazard in the coastal areas of Huon Peninsula and New Britain–Bougainville regions and a relatively low level of hazard in the southwestern part of Papua New Guinea. To identify earthquake sources that are contributing most to the overall hazard, we performed hazard disaggregation analysis for all of the major localities in PNG (e.g. Figure 9). Results of the hazard disaggregation analysis shows that in the Huon Peninsula region, the frequent moderate to large earthquakes occurring on the Ramu-Markham Fault Zone results in high seismic hazard (Figure 9). The New Britain–Bougainville region also has relatively high seismic hazard. The proximity to the subduction zone of the New Britain Trench is the main influence on the calculated level of hazard

Papua New Guinea (PNG) lies in a belt of intense tectonic activity that experiences high levels of seismicity. Although this seismicity poses significant risks to society, the Building Code of PNG and its underpinning seismic loading requirements have not been revised since 1982. This study aims to partially address this gap by updating the seismic zoning map on which the earthquake loading component of the building code is based. We performed a new probabilistic seismic hazard assessment for PNG. Among other enhancements, for the first time together with background sources, individual fault sources are implemented to represent active major and microplate boundaries in the region to better constrain the earthquake-rate and seismic-source models. The seismic-source model also models intraslab, Wadati-Benioff zone seismicity in a realistic way using a continuous slab volume to constrain the finite ruptures of such events. The results suggest a high level of hazard in the coastal areas of the Huon Peninsula and the New Britain–Bougainville region, and a relatively low level of hazard in the southern part of the New Guinea Highlands Block. In comparison with the seismic zonation map in the current design standard, it can be noted that the spatial distribution used for building design does not match the bedrock hazard distribution of this study. In particular, the high seismic hazard of the Huon Peninsula in the revised assessment is not captured in the current building code of PNG. We will also discuss how the seismic hazard map of PNG is being used to underpin its building code, including what steps have been taken by GA together with the Government of PNG to promote uptake of the new hazard map by PNG’s earthquake engineering community.