Impact of the Hunga Tonga volcanic eruption on stratospheric composition.

The explosive eruption of the Hunga Tonga-Hunga Ha'apai (HTHH) volcano on 15 January 2022 injected more water vapor into the stratosphere and to higher altitudes than ever observed in the satellite era. Here, the evolution of the stratospherically injected water vapor is examined as a function of latitude, altitude, and time in the year following the eruption (February to December 2022), and perturbations to stratospheric chemical composition resulting from the increased sulfate aerosols and water vapor are identified and analyzed. The average calculated mass distribution of elevated water vapor between hemispheres is approximately 78% Southern Hemisphere (SH) and 22% Northern Hemisphere in 2022. Significant changes in stratospheric composition following the HTHH eruption are identified using observations from the Aura Microwave Limb Sounder satellite instrument. The dominant features in the monthly mean vertical profiles averaged over 15° latitude ranges are decreases in O3 (-14%) and HCl (-22%) at SH midlatitudes and increases in ClO (>100%) and HNO3 (43%) in the tropics, with peak pressure-level perturbations listed. Anomalies in column ozone from 1.2-100 hPa due to the HTHH eruption include widespread O3 reductions in SH midlatitudes and O3 increases in the tropics, with peak anomalies in 15° latitude-binned, monthly averages of approximately -7% and +5%, respectively, occurring in austral spring. Using a 3-dimensional chemistry-climate-aerosol model and observational tracer correlations, changes in stratospheric composition are found to be due to both dynamical and chemical factors.

Unexpectedly rapid aerosol formation in the Hunga Tonga plume.

The Hunga Tonga-Hunga Ha'apai (HT-HH) volcanic eruptions on January 13 and 15, 2022, produced a plume with the highest signal in stratospheric aerosol optical depth observed since the eruption of Mt. Pinatubo in 1991. Suites of balloon-borne instruments on a series of launches from Réunion Island intercepted the HT-HH plume between 7 and 10 d of the eruptions, yielding observations of the aerosol number and size distribution and sulfur dioxide (SO2) and water vapor (H2O) concentrations. The measurements reveal an unexpected abundance of large particles in the plume, constrain the total sulfur injected to approximately 0.2 Tg, provide information on the altitude of the injection, and indicate that the formation of sulfuric acid aerosol was complete within 3 wk. Large H2O enhancements contributed as much as ~30% to ambient aerosol surface area and likely accelerated SO2 oxidation and aerosol formation rates in the plume to approximately three times faster than under normal stratospheric conditions.

Effects of inappropriate cause-of-death certification on mortality from cardiovascular disease and diabetes mellitus in Tonga.

BACKGROUND: Cardiovascular disease (CVD) and diabetes mellitus are major health issues in Tonga and other Pacific countries, although mortality levels and trends are unclear. We assess the impacts of cause-of-death certification on coding of CVD and diabetes as underlying causes of death (UCoD). METHODS: Tongan records containing cause-of-death data (2001-2018), including medical certificates of cause-of-death (MCCD), had UCoD assigned according to International Classification of Diseases 10th revision (ICD-10) coding rules. Deaths without recorded cause were included to ascertain total mortality. Diabetes and hypertension causes were reallocated from Part 1 of the MCCD (direct cause) to Part 2 (contributory cause) if potentially fatal complications were not recorded, and an alternative UCoD was assigned. Proportional mortality by cause based on the alternative UCoD were applied to total deaths then mortality rates calculated by age and sex using census/intercensal population estimates. CVD and diabetes mortality rates for unaltered and alternative UCoD were compared using Poisson regression. RESULTS: Over 2001-18, in ages 35-59 years, alternative CVD mortality was higher than unaltered CVD mortality in men (p = 0.043) and women (p = 0.15); for 2010-18, alternative versus unaltered measures in men were 3.3/103 (95%CI: 3.0-3.7/103) versus 2.9/103 (95%CI: 2.6-3.2/103), and in women were 1.1/103 (95%CI: 0.9-1.3/103) versus 0.9/103 (95%CI: 0.8-1.1/103). Conversely, alternative diabetes mortality rates were significantly lower than the unaltered rates over 2001-18 in men (p < 0.0001) and women (p = 0.013); for 2010-18, these measures in men were 1.3/103 (95%CI: 1.1-1.5/103) versus 1.9/103 (95%CI: 1.6-2.2/103), and in women were 1.4/103 (95%CI: 1.2-1.7/103) versus 1.7/103 (95%CI: 1.5-2.0/103). Diabetes mortality rates increased significantly over 2001-18 in men (unaltered: p < 0.0001; alternative: p = 0.0007) and increased overall in women (unaltered: p = 0.0015; alternative: p = 0.014). CONCLUSIONS: Diabetes reporting in Part 1 of the MCCD, without potentially fatal diabetes complications, has led to over-estimation of diabetes, and under-estimation of CVD, as UCoD in Tonga. This indicates the importance of controlling various modifiable risks for atherosclerotic CVD (including stroke) including hypertension, tobacco use, and saturated fat intake, besides obesity and diabetes. Accurate certification of diabetes as a direct cause of death (Part 1) or contributory factor (Part 2) is needed to ensure that valid UCoD are assigned. Examination of multiple cause-of-death data can improve understanding of the underlying causes of premature mortality to better inform health planning.

Investigating the health status of primary school children in Tonga: Lessons learnt and reflections on field work in the Pacific Islands.

Globally, the child health focus has been on reducing under-5-year mortality, with large populations in low-resource regions prioritised. Children in older age groups, particularly in less populated regions such as the Pacific, have received limited attention. Child health research in the Pacific region has been lacking, and research approaches for the region have historically been from Western biomedical paradigms. We completed the study of primary school children's health over a period of 5 years. Firstly, we conducted a literature review, then we completed an audit of hospital admissions of primary school children, then we completed a two-round Delphi process and finally, we piloted the survey in three primary schools. Our results found there were high levels of oral health problems, ear health, obesity and exposure to violence and poverty impacting on the quality of health of primary school-age children. Identifying these indicators was made possible by the partnerships and trust established by the study team and provides specific and measurable targets for future work to improve the quality of child health outcomes. This paper describes key field work lessons learnt for research in the Pacific region. It must: (i) be on the platform of relationship, cultural safety and local ownership; (ii) include consideration of holistic Pacific paradigms of health; (iii) be adaptive to the context and environment; and (iv) be committed to long-term partnership and work.

Quantized Information in Spectral Cyberspace.

The constant-Q Gabor atom is developed for spectral power, information, and uncertainty quantification from time-frequency representations. Stable multiresolution spectral entropy algorithms are constructed with continuous wavelet and Stockwell transforms. The recommended processing and scaling method will depend on the signature of interest, the desired information, and the acceptable levels of uncertainty of signal and noise features. Selected Lamb wave signatures and information spectra from the 2022 Tonga eruption are presented as representative case studies. Resilient transformations from physical to information metrics are provided for sensor-agnostic signal processing, pattern recognition, and machine learning applications.

Tracking the 2022 Hunga Tonga-Hunga Ha'apai Aerosol Cloud in the Upper and Middle Stratosphere Using Space-Based Observations.

On 15 January 2022, the submarine Hunga Tonga volcanic eruption lofted materials high into the upper stratosphere, reaching a record-breaking altitude of ∼58 km, unprecedented in the satellite observations era. Within two weeks, the bulk of the injected material circulated the globe between 20-30 km altitude, as observed by satellite instruments. We estimate that the stratospheric aerosol optical depth (sAOD) is the largest since the Pinatubo eruption and is at least twice as great as the sAOD after the 2015 Calbubo eruption despite the similar SO2 injection from that eruption. We use space-based observations to monitor the Hunga-Tonga volcanic plume evolution and transport at different altitudes as it circulates the globe. While the main aerosol layer remains trapped in the tropical pipe, small parts have already made it to both the northern and southern hemisphere poles by April, which is almost certain to influence this year's ozone hole.

Surviving versus thriving: The wellbeing of primary school aged children in Tonga.

AIM: To enable improvements in global child health, the focus must move beyond child survival to child wellbeing. In the Pacific Islands, the wellbeing of children has received little attention. This study aimed to investigate the wellbeing of children from three primary schools in Tonga. METHODS: A cross-sectional survey was completed in three primary schools in Nuku'alofa with children aged 5-15 years. The study participants (256 children, 143 caregivers) completed the Child Health and Illness Profile - Child Edition, CHIP-CE (Version 1.0). RESULTS: On average, >70% of children and caregivers described home and school environments as positive. From the children's reports, boys had significantly lower scores for risk avoidance than girls (3.40 vs. 3.73, P < 0.001). Children aged 5-7 versus 8-15 years had significantly lower scores for satisfaction (3.63 vs. 3.92, P = 0.002), resilience (3.34 vs. 3.56, P = 0.016) and achievement (3.25 vs. 3.62, P = 0.002). From the caregivers' report, girls had significantly lower scores for academic performance than boys (3.60 vs. 3.81, P = 0.04). Boys had significantly lower scores for individual risk association compared to girls (3.93 vs. 4.29, P = 0.01). Overall CHIP-CE scores were lower than those of comparable populations in the West, while at the same time protective factors were documented. CONCLUSIONS: Understanding child wellbeing in the Pacific is critical for strengthening protective factors known to mitigate poor child health outcomes. Continuing to base global child health success on child survival alone misses opportunities for improving the wellbeing of nations.

Tsunami Effects on the Coast of Mexico by the Hunga Tonga-Hunga Ha'apai Volcano Eruption, Tonga.

The massive explosion by the January 15, 2022 Hunga Tonga-Hunga Ha'apai volcano in Tonga triggered a trans-oceanic tsunami generated by coupled ocean and atmospheric shock waves during the explosion. The tsunami reached first the coast of Tonga, and later many coasts around the world. The shock wave went around the globe, causing sea perturbations as far as the Caribbean and the Mediterranean seas. We present the effects of the January 15, 2022 Tonga tsunami on the Mexican Pacific Coast, Gulf of Mexico, and Mexican Caribbean coast, and discuss the underrated hazard caused by great volcanic explosions, and the role of early tsunami warning systems, in particular in Mexico. The shock wave took about 7.5 h to reach the coast of Mexico, located about 9000 km away from the volcano, and the signal lasted several hours, about 133 h (5.13 days). The shock wave was the only cause for sea alterations on the Gulf of Mexico and Caribbean Sea, while at the Mexican Pacific coast both shock wave and the triggered tsunami by the volcano eruption and collapse affected this coast. The first tsunami waves recorded on the Mexican Pacific coast arrived around 12:35 on January 15, at the Lázaro Cárdenas, Michoacán tide gauge station. The maximum tsunami height exceeded 2 m at the Ensenada, Baja California, and Manzanillo, Colima, tide gauge stations. Most tsunami warning advisories, with two exceptions, reached communities via social media (Twitter and Facebook), but did not clearly state that people must stay away from the shore. We suggest that, although no casualties were reported in Mexico, tsunami warning advisories of far-field tsunamis and those triggered non-seismic sources, such as landslides and volcanic eruptions, should be included and improved to reach coastal communities timely, explaining the associated hazards on the coast. Supplementary Information: The online version contains supplementary material available at 10.1007/s00024-022-03017-9.

Preliminary Observations and Impact in Japan of the Tsunami Caused by the Tonga Volcanic Eruption on January 15, 2022.

The tsunami caused by the Tonga submarine volcanic eruption that occurred at 13:15 Japan Time (JST) on January 15, 2022, exposed a blind spot in Japan's tsunami monitoring and warning system, which was established in 1952 for local tsunamis and expanded to distant tsunamis after the 1960 Chile tsunami. This paper summarizes how the warning system responded to the unprecedented tsunami, the actual evacuation process, and the damage it caused in Japan. Initially, the tsunami from the volcanic eruption was expected to arrive at approximately midnight with amplitudes of less than 20 cm. However, a series of short waves arrived at approximately 21:00, a few hours earlier than expected. The early arrival of these sea waves coincided with a rapid increase in atmospheric pressure; then, the short-period component was predominant, and the wave height was amplified while forming wave groups. After a 1.2 m tsunami was observed in Amami City in southern Japan at 23:55 JST, the Japan Meteorological Agency issued a tsunami warning/advisory. The tsunami continued, and all advisories were cleared at 14:00 JST on January 16. Information about this tsunami and the response to it are summarized here, including the characteristics and issues of the actual tsunami evacuation situation in each region. There were no casualties, but the issues that emerged included difficulty evacuating on a winter night and traffic congestion due to evacuation by car and under the conditions of the COVID-19 pandemic. In the coastal area, damage to fishing boats and aquaculture facilities was reported due to the flow of the tsunami. In addition, damage to aquaculture facilities, including those producing oysters, scallops, seaweed and other marine products, decreased the supply of marine products, and the economic impact is likely to increase in the future.

Barriers and facilitators to the introduction of import duties designed to prevent noncommunicable disease in Tonga: a case study.

BACKGROUND: In Tonga, import duties were lowered on tinned fish and seafood in 2013 and raised on soft drinks, dripping and other animal fats. Additional import duties were applied to soft drinks and dripping and other fats in 2016 and duties were also applied to high fat meats, mutton flaps and turkey tails. The objective of this study was to describe barriers to and facilitators of these import duties from a policy-maker perspective. METHODS: A case study was conducted to analyse implementation of policies originally modelled by the Pacific Obesity Prevention in Communities project to reduce mortality in the Kingdom of Tonga. Policymakers (n = 15) from the Ministries of Revenue, Health, Finance and Labour and Commerce involved in the development and implementation of Tonga's food-related policies participated in key-informant interviews. RESULTS: The main facilitator of import duties were strong leadership and management, cross-sector collaboration, awareness raising and advocacy, nature of the policy, and the effective use of data to model policy impacts and inform the general public. The absence of clear lines of responsibility and a decline in collaboration over time were identified as barriers to implementation of the import duties. CONCLUSION: In a small Island state implementing import duties to prevent non-communicable disease can be straight forward providing policymakers and the community have a shared understanding of the health and economic costs of NCDs.

Equity of expenditure changes associated with a sweetened-beverage tax in Tonga: repeated cross-sectional household surveys.

BACKGROUND: The aim of this study was to examine changes in beverage expenditure patterns before and after a T$0.50/L sweetened-beverage (SB) excise was introduced in Tonga in 2013, by household income, household age composition and island of residence. METHODS: Two cross-sectional surveys involved households being randomly sampled (the Household Income and Expenditure Surveys in 2009 (n = 1982) and 2015/16 (n = 1800)). Changes in soft drink (taxed), bottled water, and milk (both untaxed) expenditure were examined namely: (i) prevalence of households purchasing the beverage; (ii) average expenditure per person (inflation-adjusted); (iii) expenditure as a proportion of household food budget; and (iv) expenditure per person as a proportion of equivalised income. RESULTS: The pattern found was of decreases in all soft drink expenditure outcomes and these appeared to be greater in low-income than high-income households for purchasing prevalence (- 30% and - 25% respectively, t-test p = 0.98), per-capita expenditure (- 37% and - 34%, p = 0.20) and food budget share (- 27% and - 7%, p = 0.65), but not income share (- 6% and - 32%, p = 0.71). The large expenditure increases in bottled water appeared to be greater in low-income than high-income households for purchasing prevalence (355 and 172%, p = 0.32) and food budget share (665 and 468%, p = 0.09), but greater in high-income households for per-capita expenditure (121 and 373%, p < 0.01) and income share (83 and 397%, p = 0.50). CONCLUSIONS: The sweetened-beverage tax was associated with reduced soft drink purchasing and increased bottled water expenditure. Low-income households appeared to have slightly greater declines in soft drink expenditure.

Living with type 2 diabetes mellitus in the Kingdom of Tonga: a qualitative investigation of the barriers and enablers to lifestyle management.

BACKGROUND: Despite the increasing prevalence of Type 2 Diabetes Mellitus (T2DM) in the Kingdom of Tonga, little is known of non-communicable disease experiences among adults living in this location. This investigation aimed to explore the barriers and enablers to healthy lifestyle in a group of men and women living with T2DM residing in this Pacific Island nation. METHODS: This qualitative study consisted of three semi-structured focus groups (n = 16), conducted at the only Tongan Public Hospital located at Nuku'alofa, capital of Tonga (north coast of the island of Tongatapu). Discussions were audio-recorded, transcribed, cross-checked for consistency, and entered into a word processing document for analysis. Thematic analysis was employed to synthesise results. RESULTS: Four main themes were identified: (1) Knowledge and Support; (2) Fear and Motivation; 3) Physical and Psychological Environment; and (4) Faith and Culture. CONCLUSIONS: The qualitative findings from this study will assist the future development and information dissemination of culturally appropriate lifestyle-related for men and women living with T2DM in the Kingdom of Tonga. The need for collaboration between practitioners at the hospital, the church, family members, and local traditional healers is important if the lifestyle-related needs and wants of this group of people are to be met.

Mortality in Tonga over three triennia, 2010-2018.

BACKGROUND: Tonga is a South Pacific Island country with a population of 100,651 (2016 Census). This study examines Tongan infant mortality rates (IMR), under-five mortality rates (U5MR), adult mortality and life expectancy (LE) at birth from 2010 to 2018 using a recent collation of empirical mortality data over the past decade for comparison with other previously published mortality estimates. METHODS: Routinely collected mortality data for 2010-2018 from the Ministry of Health, national (Vaiola) hospital, community nursing reports, and the Civil Registry, were consolidated by deterministic and probabilistic linkage of individual death records. Completeness of empirical mortality reporting was assessed by capture-recapture analysis. The reconciled data were aggregated into triennia to reduce stochastic variation, and used to estimate IMR and U5MR (per 1000 live births), adult mortality (15-59, 15-34, 35-59, and 15-64 years), and LE at birth, employing the hypothetical cohort method (with statistical testing). Mortality trends and differences were assessed by Poisson regression. Mortality findings were compared with published national and international agency estimates. RESULTS: Over the three triennia in 2010-2018, levels varied minimally for IMR (12-14) and U5MR (15-19) per 1000 births (both ns, p > 0.05), and also for male LE at birth of 64-65 years, and female LE at birth 69-70 years. Cumulated risks of adult mortality were significantly higher in men than women; period mortality increases in 15-59-year women from 18 to 21% were significant (p < 0.05). Estimated completeness of the reconciled data was > 95%. International agencies reported generally comparable estimates of IMR and U5MR, with varying uncertainty intervals; but they reported significantly lower adult mortality and higher LE than the empirical estimates from this study. CONCLUSIONS: Life expectancy in Tonga over 2010-2018 has remained relatively low and static, with low IMR and U5MR, indicating the substantial impact from premature adult mortality. This analysis of empirical data (> 95% complete) indicates lower LE and higher premature adult mortality than previously reported by international agencies using indirect and modelled methods. Continued integration of mortality recording and data systems in Tonga is important for improving the completeness and accuracy of mortality estimation for local health monitoring and planning.

Natural Products from Tongan Marine Organisms.

The islands of the South Pacific Ocean have been in the limelight for natural product biodiscovery, due to their unique and pristine tropical waters and environment. The Kingdom of Tonga is an archipelago in the central Indo-Pacific Ocean, consisting of 176 islands, 36 of which are inhabited, flourishing with a rich diversity of flora and fauna. Many unique natural products with interesting bioactivities have been reported from Indo-Pacific marine sponges and other invertebrate phyla; however, there have not been any reviews published to date specifically regarding natural products from Tongan marine organisms. This review covers both known and new/novel Marine Natural Products (MNPs) and their biological activities reported from organisms collected within Tongan territorial waters up to December 2020, and includes 109 MNPs in total, the majority from the phylum Porifera. The significant biological activity of these metabolites was dominated by cytotoxicity and, by reviewing these natural products, it is apparent that the bulk of the new and interesting biologically active compounds were from organisms collected from one particular island, emphasizing the geographic variability in the chemistry between these organisms collected at different locations.

Sweetened beverage taxes and changes in beverage price, imports and manufacturing: interrupted time series analysis in a middle-income country.

BACKGROUND: The Pacific Island nation of Tonga (a middle-income country) introduced a sweetened beverage tax of T$0.50/L in 2013, with this increasing further in 2016 (to T$1.00/L), and in 2017 (T$1.50/L; US$0.02/oz). Given the potential importance of such types of fiscal intervention for preventing chronic disease, we aimed to evaluate the impact of these tax changes in Tonga. METHODS: Interrupted time series analysis was used to examine monthly import volumes and quarterly price and manufacturing 1 year after each tax change, compared with a counterfactual based on existing trends. Autocorrelation was adjusted for when present, and adjustments were made for changes in GDP per capita, visitor numbers, season and T$/US$ exchange rate. RESULTS: In the year after the 2013, 2016 and 2017 tax increases, the price of an indicator soft drink increased by 16.8% (95%CI: 6.3 to 29.6), 3.7% (- 0.6 to 8.3) and 17.6% (6.0 to 32.0) respectively. Imports of sweetened beverages decreased with changes of - 10.4% (- 23.6 to 9.0), - 30.3% (- 38.8 to - 20.5) and - 62.5% (- 73.1 to - 43.4) respectively. Juice imports changed by - 54.2% (- 93.2 to - 1.1), and sachet drinks by - 15.5% (- 67.8 to 88.3) after the 2017 tax increase. Tonga water bottling (T$) increased in value by 143% (69 to 334) after the 2016 tax increase and soft drink manufacturing increased by 20% (2 to 46, albeit 5% market share). CONCLUSIONS: Consistent with international evaluations of sugar-sweetened beverage taxes, the taxes in Tonga were associated with increased prices, decreased taxed beverages imports, and increased locally bottled water.

Falling into a deep dark hole: Tongan people's perceptions of being at risk of developing type 2 diabetes.

BACKGROUND: Prediabetes is a precursor for type 2 diabetes. Compared to the New Zealand/European and other population groups (24.6%), the prevalence of prediabetes is higher within Pacific groups (29.8%). The diagnosis of prediabetes presents a potential opportunity to intervene to prevent progression to type 2 diabetes. OBJECTIVE: To develop an understanding of how being 'at risk' of developing type 2 diabetes is perceived by Tongan people with prediabetes living in Auckland, New Zealand. METHODS: The Kakala and Talanga Tongan methodologies underpinned this study. Twelve one-on-one, semi-structured interviews with Tongan patients who had prediabetes from a primary health-care clinic in Auckland, New Zealand, were conducted. Thematic analysis was used to identify recurrent themes from the data. RESULTS: Participants were not aware of their prediabetes diagnosis, emotions associated with the diagnosis reflected fear and disbelief and a perception of imminent danger. Family history informed perceptions of the risk of developing type 2 diabetes. Participants could not differentiate prediabetes from type 2 diabetes, and recollections of being 'back in the Islands' of Tonga were consistent with healthy lifestyles. CONCLUSIONS: Prediabetes appeared to be poorly understood and was believed to be irreversible, which could discourage behaviour change, social and physical improvements in health. Appropriate culturally tailored messages to accompany a prediabetes diagnosis, including cause and management, would be beneficial for Pacific peoples.

Monitoring and Modeling the Rapid Evolution of Earth's Newest Volcanic Island: Hunga Tonga Hunga Ha'apai (Tonga) Using High Spatial Resolution Satellite Observations.

We have monitored a newly erupted volcanic island in the Kingdom of Tonga, unofficially known as Hunga Tonga Hunga Ha'apai, by means of relatively frequent high spatial resolution (~50 cm) satellite observations. The new ~1.8 km2 island formed as a tuff cone over the course of a month-long hydromagmatic eruption in early 2015 in the Tonga-Kermadec volcanic arc. Such ash-dominated eruptions usually produce fragile subaerial landscapes that wash away rapidly due to marine erosion, as occurred nearby in 2009. Our measured rates of erosion are ~0.00256 km3/year from derived digital topographic models. Preliminary measurements of the topographic expression of the primary tuff cone over ~30 months suggest a lifetime of ~19 years (and potentially up to 42 years). The ability to measure details of a young island's landscape evolution using satellite remote sensing has not previously been possible at these spatial and temporal resolutions.

Southwest Pacific Absolute Plate Kinematic Reconstruction Reveals Major Cenozoic Tonga-Kermadec Slab Dragging.

Tectonic plates subducting at trenches having strikes oblique to the absolute subducting plate motion undergo trench-parallel slab motion through the mantle, recently defined as a form of "slab dragging." We investigate here long-term slab-dragging components of the Tonga-Kermadec subduction system driven by absolute Pacific plate motion. To this end we develop a kinematic restoration of Tonga-Kermadec Trench motion placed in a mantle reference frame and compare it to tomographically imaged slabs in the mantle. Estimating Tonga-Kermadec subduction initiation is challenging because another (New Caledonia) subduction zone existed during the Paleogene between the Australia and Pacific plates. We test partitioning of plate convergence across the Paleogene New Caledonia and Tonga-Kermadec subduction zones against resulting mantle structure and show that most, if not all, Tonga-Kermadec subduction occurred after ca. 30 Ma. Since then, Tonga-Kermadec subduction has accommodated 1,700 to 3,500 km of subduction along the southern and northern ends of the trench, respectively. When placed in a mantle reference frame, the predominantly westward directed subduction evolved while the Tonga-Kermadec Trench underwent ~1,200 km of northward absolute motion. We infer that the entire Tonga-Kermadec slab was laterally transported through the mantle over 1,200 km. Such slab dragging by the Pacific plate may explain observed deep-slab deformation and may also have significant effects on surface tectonics, both resulting from the resistance to slab dragging by the viscous mantle.

Molecular Identification of Gambierdiscus and Fukuyoa (Dinophyceae) from Environmental Samples.

Ciguatera Fish Poisoning (CFP) is increasing across the Pacific and the distribution of the causative dinoflagellates appears to be expanding. Subtle differences in thecal plate morphology are used to distinguish dinoflagellate species, which are difficult to determine using light microscopy. For these reasons we sought to develop a Quantitative PCR assay that would detect all species from both Gambierdiscus and Fukuyoa genera in order to rapidly screen environmental samples for potentially toxic species. Additionally, a specific assay for F. paulensis was developed as this species is of concern in New Zealand coastal waters. Using the assays we analyzed 31 samples from three locations around New Zealand and the Kingdom of Tonga. Fourteen samples in total were positive for Gambierdiscus/Fukuyoa and two samples were also positive using the F. paulensis assay. Samples from the Kermadec Islands were further characterized using high-throughput sequencing metabarcoding. The majority of reads corresponded to Gambierdiscus species with three species identified at all sites (G. australes, G. honu and G. polynesiensis). This is the first confirmed identification of G. polynesiensis, a known ciguatoxin producer, in New Zealand waters. Other known toxin-producing genera were also detected, included Alexandrium, Amphidinium, Azadinium, Dinophysis, Ostreopsis, and Prorocentrum.

Identification of Source of Brucella suis Infection in Human by Using Whole-Genome Sequencing, United States and Tonga.

Brucella suis infection was diagnosed in a man from Tonga, Polynesia, who had butchered swine in Oregon, USA. Although the US commercial swine herd is designated brucellosis-free, exposure history suggested infection from commercial pigs. We used whole-genome sequencing to determine that the man was infected in Tonga, averting a field investigation.