The largest volcanic eruptions on Earth

Large igneous provinces (LIPs) are sites of the most frequently recurring, largest volume basaltic and silicic eruptions in Earth history. These large-volume (N1000 km3 dense rock equivalent) and large-magnitude (NM8) eruptions produce areally extensive (104–105 km2) basaltic lava flow fields and silicic ignimbrites that are the main building blocks of LIPs. Available information on the largest eruptive units are primarily from the Columbia River and Deccan provinces for the dimensions of flood basalt eruptions, and the Paraná–Etendeka and Afro-Arabian provinces for the silicic ignimbrite eruptions. In addition, three large-volume (675– 2000 km3) silicic lava flows have also been mapped out in the Proterozoic Gawler Range province (Australia), an interpreted LIP remnant. Magma volumes of N1000 km3 have also been emplaced as high-level basaltic and rhyolitic sills in LIPs. The data sets indicate comparable eruption magnitudes between the basaltic and silicic eruptions, but due to considerable volumes residing as co-ignimbrite ash deposits, the current volume constraints for the silicic ignimbrite eruptions may be considerably underestimated. Magma composition thus appears to be no barrier to the volume of magma emitted during an individual eruption. Despite this general similarity in magnitude, flood basaltic and silicic eruptions are very different in terms of eruption style, duration, intensity, vent configuration, and emplacement style. Flood basaltic eruptions are dominantly effusive and Hawaiian–Strombolian in style, with magma discharge rates of ~106–108 kg s−1 and eruption durations estimated at years to tens of years that emplace dominantly compound pahoehoe lava flow fields. Effusive and fissural eruptions have also emplaced some large-volume silicic lavas, but discharge rates are unknown, and may be up to an order of magnitude greater than those of flood basalt lava eruptions for emplacement to be on realistic time scales (b10 years). Most silicic eruptions, however, are moderately to highly explosive, producing co-current pyroclastic fountains (rarely Plinian) with discharge rates of 109– 1011 kg s−1 that emplace welded to rheomorphic ignimbrites. At present, durations for the large-magnitude silicic eruptions are unconstrained; at discharge rates of 109 kg s−1, equivalent to the peak of the 1991 Mt Pinatubo eruption, the largest silicic eruptions would take many months to evacuate N5000 km3 of magma. The generally simple deposit structure is more suggestive of short-duration (hours to days) and high intensity (~1011 kg s−1) eruptions, perhaps with hiatuses in some cases. These extreme discharge rates would be facilitated by multiple point, fissure and/or ring fracture venting of magma. Eruption frequencies are much elevated for large-magnitude eruptions of both magma types during LIP-forming episodes. However, in basaltdominated provinces (continental and ocean basin flood basalt provinces, oceanic plateaus, volcanic rifted margins), large magnitude (NM8) basaltic eruptions have much shorter recurrence intervals of 103–104 years, whereas similar magnitude silicic eruptions may have recurrence intervals of up to 105 years. The Paraná– Etendeka province was the site of at least nine NM8 silicic eruptions over an ~1 Myr period at ~132 Ma; a similar eruption frequency, although with a fewer number of silicic eruptions is also observed for the Afro- Arabian Province. The huge volumes of basaltic and silicic magma erupted in quick succession during LIP events raises several unresolved issues in terms of locus of magma generation and storage (if any) in the crust prior to eruption, and paths and rates of ascent from magma reservoirs to the surface.

Measurement of total body water (TBW) and total energy expenditure (TEE) using stable isotopes

Understanding the relationship between diet, physical activity and health in humans requires accurate measurement of body composition and daily energy expenditure. Stable isotopes provide a means of measuring total body water and daily energy expenditure under free-living conditions. While the use of isotope ratio mass spectrometry (IRMS) for the analysis of 2H (Deuterium) and 18O (Oxygen-18) is well established in the field of human energy metabolism research, numerous questions remain regarding the factors which influence analytical and measurement error using this methodology. This thesis was comprised of four studies with the following emphases. The aim of Study 1 was to determine the analytical and measurement error of the IRMS with regard to sample handling under certain conditions. Study 2 involved the comparison of TEE (Total daily energy expenditure) using two commonly employed equations. Further, saliva and urine samples, collected at different times, were used to determine if clinically significant differences would occur. Study 3 was undertaken to determine the appropriate collection times for TBW estimates and derived body composition values. Finally, Study 4, a single case study to investigate if TEE measures are affected when the human condition changes due to altered exercise and water intake. The aim of Study 1 was to validate laboratory approaches to measure isotopic enrichment to ensure accurate (to international standards), precise (reproducibility of three replicate samples) and linear (isotope ratio was constant over the expected concentration range) results. This established the machine variability for the IRMS equipment in use at Queensland University for both TBW and TEE. Using either 0.4mL or 0.5mL sample volumes for both oxygen-18 and deuterium were statistically acceptable (p>0.05) and showed a within analytical variance of 5.8 Delta VSOW units for deuterium, 0.41 Delta VSOW units for oxygen-18. This variance was used as “within analytical noise” to determine sample deviations. It was also found that there was no influence of equilibration time on oxygen-18 or deuterium values when comparing the minimum (oxygen-18: 24hr; deuterium: 3 days) and maximum (oxygen-18: and deuterium: 14 days) equilibration times. With regard to preparation using the vacuum line, any order of preparation is suitable as the TEE values fall within 8% of each other regardless of preparation order. An 8% variation is acceptable for the TEE values due to biological and technical errors (Schoeller, 1988). However, for the automated line, deuterium must be assessed first followed by oxygen-18 as the automated machine line does not evacuate tubes but merely refills them with an injection of gas for a predetermined time. Any fractionation (which may occur for both isotopes), would cause a slight elevation in the values and hence a lower TEE. The purpose of the second and third study was to investigate the use of IRMS to measure the TEE and TBW of and to validate the current IRMS practices in use with regard to sample collection times of urine and saliva, the use of two TEE equations from different research centers and the body composition values derived from these TEE and TBW values. Following the collection of a fasting baseline urine and saliva sample, 10 people (8 women, 2 men) were dosed with a doubly labeled water does comprised of 1.25g 10% oxygen-18 and 0.1 g 100% deuterium/kg body weight. The samples were collected hourly for 12 hrs on the first day and then morning, midday, and evening samples were collected for the next 14 days. The samples were analyzed using an isotope ratio mass spectrometer. For the TBW, time to equilibration was determined using three commonly employed data analysis approaches. Isotopic equilibration was reached in 90% of the sample by hour 6, and in 100% of the sample by hour 7. With regard to the TBW estimations, the optimal time for urine collection was found to be between hours 4 and 10 as to where there was no significant difference between values. In contrast, statistically significant differences in TBW estimations were found between hours 1-3 and from 11-12 when compared with hours 4-10. Most of the individuals in this study were in equilibrium after 7 hours. The TEE equations of Prof Dale Scholler (Chicago, USA, IAEA) and Prof K.Westerterp were compared with that of Prof. Andrew Coward (Dunn Nutrition Centre). When comparing values derived from samples collected in the morning and evening there was no effect of time or equation on resulting TEE values. The fourth study was a pilot study (n=1) to test the variability in TEE as a result of manipulations in fluid consumption and level of physical activity; the magnitude of change which may be expected in a sedentary adult. Physical activity levels were manipulated by increasing the number of steps per day to mimic the increases that may result when a sedentary individual commences an activity program. The study was comprised of three sub-studies completed on the same individual over a period of 8 months. There were no significant changes in TBW across all studies, even though the elimination rates changed with the supplemented water intake and additional physical activity. The extra activity may not have sufficiently strenuous enough and the water intake high enough to cause a significant change in the TBW and hence the CO2 production and TEE values. The TEE values measured show good agreement based on the estimated values calculated on an RMR of 1455 kcal/day, a DIT of 10% of TEE and activity based on measured steps. The covariance values tracked when plotting the residuals were found to be representative of “well-behaved” data and are indicative of the analytical accuracy. The ratio and product plots were found to reflect the water turnover and CO2 production and thus could, with further investigation, be employed to identify the changes in physical activity.

Institutional response and Indigenous experiences of Cyclone Tracy

Early on Christmas morning 1974 Tropical Cyclone Tracy, a Category 4 storm, devastated the Northern Territory city of Darwin leaving only 6% of the city’s housing habitable. The extent of the disaster was largely the result of unregulated and poorly constructed buildings, predominantly housing. While the engineering and reconstruction process demonstrated a very successful response and adaptation to an existing and future risk, the impact of the cyclone of the local community and its Indigenous population in particular, had not been well recorded. NCCARF therefore commissioned a report on the Indigenous experience of Cyclone Tracy to document how Indigenous people were impacted by, responded to, and recovered from Cyclone Tracy in comparison to non-Indigenous groups. The report also considers the research literature on disasters and Indigenous people in the Northern Territory, with a specific focus on cyclones, and considers the socio-political context of Indigenous communities in Darwin prior to Cyclone Tracy.

Displaced twice? Talking about resilience with a cohort of men from refugee backgrounds who were affected by the 2011 Queensland floods

What can we learn from people from refugee backgrounds who have been affected by an environmental disaster? This paper presents the first year findings of a study that is investigating the impact of the 2011 Queensland floods on a cohort of men from refugee backgrounds living in Brisbane and the Toowoom- ba–Gatton region of Southeast Queensland. Between 2008 and 2010, the SettleMEN study yielded pre-disaster measures of health and settlement among 233 refugee men. The current 2012−2013 follow-up study offers a rare opportunity to investigate and describe the impact of an environmental disaster on the health and wellbeing of a group of resettled refugee men who were affected by the 2011 Queensland floods. Using a mixed-method approach and a peer interviewer model, this paper reports on the exposure to and impact of the floods on the first 100 respondents who were interviewed between September 2012 and March 2013. Overall, we have found that the floods had a considerable economic and psychosocial impact on this group of men, their families and communities in terms of being forced to evacuate their homes, work disrup- tion, loss of income and personal belongings, and emotional distress. Many of these men reported that their previous refugee experience helped them to cope better during and after the floods, and for some, providing assistance to others during the floods impacted positively on their relationship with their neighbours. These findings challenge the Western deficits model that defines former refugees as traumatised victims. Refugee people’s strengths and capabilities should be taken into consideration when developing disaster response strategies at the neighbourhood and community levels.

Legal mechanisms for maximising community engagement with formal evacuation messaging: How well are these understood?

Study/Objective This program of research examines the effectiveness of legal mechanisms as motivators to maximise engagement and compliance with evacuation messages. This study is based on the understanding that the presence of legislative requirements, as well as sanctions and incentives encapsulated in law, can have a positive impact in achieving compliance. Our objective is to examine whether the current Australian legal frameworks, which incorporate evacuation during disasters, are an effective structure that is properly understood by those who enforce and those who are required to comply. Background In Australia, most jurisdictions have enacted legislation that encapsulates the power to evacuate and the ability to enforce compliance, either by the use of force or imposition of penalty. However, citizens still choose to not evacuate. Methods This program of research incorporates theoretical and doctrinal methodologies for reviewing literature and legislation in the Australia context. The aim of the research is to determine whether further clarity is required to create an understanding of the powers to evacuate, as well as greater public awareness of these powers. Results & Conclusion Legislators suggest that powers of evacuation can be ineffective if they are impractical to enforce. In Australia, there may also be confusion about from which legislative instrument the power to evacuate derives, and therefore whether there is a corresponding ability to enforce compliance through the use of force or imposition of a penalty. Equally, communities may lack awareness and understanding of the powers of agencies to enforce compliance. We seek to investigate whether this is the case, and whether even if greater awareness existed, it would act as an incentive to comply.

Effective emergency messaging during natural disasters: An application of message compliance theories

Study/Objective This research examines the types of emergency messages used in Australia during the response and early recovery phases of a natural disaster. The aim of the research is to develop theory-driven emergency messages that increase individual behavioural compliance during a disaster. Background There is growing evidence of non-compliant behaviour in Australia, such as refusing to evacuate and travelling through hazardous areas. This can result in personal injury, loss of life, and damage to (or loss of) property. Moreover, non-compliance can place emergency services personnel in life-threatening situations when trying to save non-compliant individuals. Drawing on message compliance research in psychology and sociology, a taxonomy of message types was developed to ascertain how emergency messaging can be improved to produce compliant behaviour. Method A review of message compliance literature was conducted to develop the taxonomy of message types previously found to achieve compliance. Seven categories were identified: direct-rational, manipulation, negative phrasing, positive phrasing, exchange appeals, normative appeals, and appeals to self. A content analysis was then conducted to assess the emergency messages evident in the Australian emergency management context. The existing messages were aligned with the literature to identify opportunities to improve emergency messaging. Results & Conclusion The results suggest there is an opportunity to improve the effectiveness of emergency messaging to increase compliance during the response and early recovery phases of a natural disaster. While some message types cannot legally or ethically be used in emergency communication (e.g. manipulative messaging), there is an opportunity to create more persuasive messages (e.g. appeals to self) that personalise the individual’s perception of risk, triggering them to comply with the message.

Faecal incontinence in childhood : a multidisciplinary approach including biofeedback

One hundred and seven children with faecal incontinence were evaluated and managed over a 3 year period by a multidisciplinary team. After initial clinical assessment, evaluation of defaecatory mechanisms (using a balloon model) and assessment of personal-social development and self-concept were undertaken. Management was based on initial bowel evacuation, short-term laxatives, and habit training involving systematic use of positive reinforcement; 69 children received biofeedback conditioning. Idiopathic megacolon with constipation and soiling was the most common finding (98 cases). Other diagnoses included previously undiagnosed neurogenic bowel (three cases), post-surgical anal anomalies (four cases), and psychogenic encopresis (two cases). Idiopathic megacolon was characterized by decreased rectal sensation, increased threshold for external sphincter relaxation and an inability to evacuate. Faecal incontinence was associated with an undesirably low social self-concept (70% of the 40 evaluated), but was not related to a delay in development (mean general developmental quotient = 105 ± 8, for the 35 tested). Family psychopathology warranting referral for family therapy was found in 14 children (13%). The management programme yielded a short-term (3 months) cure rate of 68% and a long-term (12 months) cure rate of 90%, with 10% having continued soiling which varied from occasional to several incidents/week. No significant improvement in self-concept was observed overall, although marked improvements were observed in some children. We conclude that disordered defaecatory dynamics are a major determinant of faecal incontinence in children. Undesirably low social self-concepts but normal developmental ability accompany this condition. Management is facilitated by a multidisciplinary approach, acknowledging the role of both behavioural and physiological components of the problem. This approach is effective in eradicating soiling in the majority of cases, comparing favourably with other published data.