Learn More
[1] In order to use ambient seismic noise for mapping Earth's structure, it is important to understand the spatio-temporal characteristics of the noise field. This study uses data collected during four austral winter months of 2002 to investigate New Zealand's ambient seismic noise field in the double-ocean-wave-frequency range (0.1 – 0.3 Hz). It is shown(More)
BACKGROUND In England, there is a policy of offering healthy women with straightforward pregnancies a choice of birth setting. Options may include home or a freestanding midwifery unit (FMU). Transfer rates from these settings are around 20%, and higher for nulliparous women. The duration of transfer is of interest because of the potential for delay in(More)
OBJECTIVES To describe the relationship between maternal age and intrapartum outcomes in 'low-risk' women; and to evaluate whether the relationship between maternal age and intrapartum interventions and adverse outcomes differs by planned place of birth. DESIGN Prospective cohort study. SETTING Obstetric units (OUs), midwifery units and planned home(More)
[1] Measurement of basement seismic resonance frequencies can elucidate shallow velocity structure, an important factor in earthquake hazard estimation. Ambient noise cross correlation, which is well-suited to studying shallow earth structure, is commonly used to analyze fundamental-mode Rayleigh waves and, increasingly, Love waves. Here we show via(More)
OBJECTIVES To explore whether service configuration and obstetric unit (OU) characteristics explain variation in OU intervention rates in 'low-risk' women. DESIGN Ecological study using funnel plots to explore unit-level variations in adjusted intervention rates and simple linear regression, stratified by parity, to investigate possible associations(More)
This paper presents the first continental-scale study of the crust and upper mantle shear-23 velocity (V s) structure of Canada and adjacent regions using ambient noise tomography. Continuous 24 waveform data recorded between 2003 and 2009 with 788 broadband seismograph stations in Canada 25 and adjacent regions are used in the analysis. The higher primary(More)
BACKGROUND Immersion in water during labour is an important non-pharmacological method to manage labour pain, particularly in midwifery-led care settings where pharmacological methods are limited. This study investigates the association between immersion for pain relief and transfer before birth and other maternal outcomes. METHODS A prospective cohort(More)
This paper presents the first continental-scale study of the crust and upper mantle shear-23 velocity (Vs) structure of Canada and adjacent regions using ambient noise tomography. Continuous 24 waveform data recorded between 2003 and 2009 with 788 broadband seismograph stations in Canada 25 and adjacent regions are used in the analysis. The higher primary(More)
  • 1