Time series analysis of subsidence at Tauhara and Ohaaki geothermal fields, New Zealand, observed by ALOS PALSAR interferometry during 2007–2009

ABSTRACTA study was made of the levels of oestrous activity of two indigenous breeds of sheep (Somali and Nandi) and three exotic breeds of sheep (Merino, Karakul and New Zealand Romney Marsh) over a period of 3 years, in an equatorial environment. Breed was the only significant source of variation for the length of the oestrous cycle (P < 0·01). The mean lengths of the oestrous cycle were 17·2 (s.d. 3·21), 17·5 (s.d. 2·24), 17·9 (s.d. 2·99), 17·5 (s.d. 2·57) and 16·5 (s.d. 3·41) days for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively.The mean percentage of ewes of the different breeds showing oestrus in 20-day periods were 69·8 (s.d. 22·57), 49·9 (s.d. 18·67), 63·4 (s.d. 25·70), 79·2 (s.d. 20·30) and 33·2 (s.d. 23·50) % for the Somali, Nandi, Merino, Karakul and Romney Marsh breeds, respectively. Time-series analysis did not detect any evidence of seasonal variation in oestrous activity, although there was an indication that the Merino and Romney Marsh breeds showed a marked increase in oestrous activity following, the introduction of rams. It was concluded that the variation in level of oestrous activity was short term and random.

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Climate Variability, Weather and Enteric Disease Incidence in New Zealand: Time Series Analysis

PLoS ONE ◽

10.1371/journal.pone.0083484 ◽

2013 ◽

Vol 8 (12) ◽

pp. e83484 ◽

Cited By ~ 35

Author(s):

Aparna Lal ◽

Takayoshi Ikeda ◽

Nigel French ◽

Michael G. Baker ◽

Simon Hales

Keyword(s):

Time Series ◽

New Zealand ◽

Climate Variability ◽

Time Series Analysis ◽

Disease Incidence ◽

Enteric Disease ◽

Series Analysis

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Long-range ground deformation monitoring by InSAR analysis

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-372-343-2015 ◽

2015 ◽

Vol 372 ◽

pp. 343-346 ◽

Cited By ~ 1

Author(s):

S. Rokugawa ◽

T. Nakamura

Keyword(s):

Time Series ◽

Time Series Analysis ◽

Synthetic Aperture Radar ◽

Surface Deformation ◽

Ground Deformation ◽

Synthetic Aperture ◽

Alos Palsar ◽

Envisat Asar ◽

Series Analysis ◽

Kanto District

Abstract. InSAR (Interferometric Synthetic Aperture Radar) analysis is an effective technique to map 3-dimensional surface deformation with high spatial resolution. The aim of this study was to evaluate the capability of InSAR analysis when applied to ground monitoring of an environmental disaster. We performed a time series InSAR analysis using ENVISAT/ASAR and ALOS/PALSAR data and commercial software to investigate subsidence around the Kanto District of Japan. We also investigated techniques for efficient early detection of landslides in Kyushu using time series analysis that incorporated synthetic aperture radar (SAR) images. ENVISAT/ASAR data acquired from 2003–2010 and ALOS/PALSAR data acquired from 2006–2011 were used to detect poorly expressed geomorphological deformation by conducting time series analyses of periodically acquired SAR data. In addition, to remove noise caused by geographical feature stripes or phase retardation, we applied median filtering, histogram extraction processing, and clarification of the displacement with a Laplacian filter. The main functions of the InSAR time series analysis are the calculation of phase differences between two images and the inversion with smoothness constraint for the estimation of deformation along the line of sight. The results enabled us to establish criteria for the selection of suitable InSAR data pairs, and provided the final error estimation of the derived surface deformation. The results of the analysis in the Kanto District suggested that localized areas of uplift and subsidence have occurred at irregular intervals in this area. Furthermore, the method offers the possibility of early warning of environmental disasters such as landslide and abrupt subsidence. Our results confirm the effectiveness of InSAR analysis for the monitoring of ground deformation over wide areas via the detection of localized subsidence and landslides.

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Correction: Doke, R., et al. Very Local Subsidence near the Hot Spring Region in Hakone Volcano, Japan, Inferred from InSAR Time Series Analysis of ALOS/PALSAR Data. Remote Sens. 2020, 12, 2842

Remote Sensing ◽

10.3390/rs12233881 ◽

2020 ◽

Vol 12 (23) ◽

pp. 3881

Author(s):

Ryosuke Doke ◽

George Kikugawa ◽

Kazuhiro Itadera

Keyword(s):

Time Series ◽

Time Series Analysis ◽

Hot Spring ◽

Alos Palsar ◽

Hakone Volcano ◽

Series Analysis

The authors wish to make the following corrections to this paper [...]

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Inferences about the effect of lockdowns on mental health require causal identification strategies: A reply to Thornley et al.

10.31234/osf.io/u7jfa ◽

2022 ◽

Author(s):

Matt N Williams ◽

Stephen Robert Hill

Keyword(s):

Mental Health ◽

Time Series ◽

New Zealand ◽

Time Series Analysis ◽

Child Mental Health ◽

Detrimental Effect ◽

Series Analysis

This letter responds to another letter in the journal (Thorney et al., 2021). Thornley et al. reported a time series analysis of "parasuicide" cases in New Zealand children and concluded that this time series demonstrates a "clear detrimental effect of COVID-19 lockdown policies on child mental health”. In this letter, we point out four reasons why this conclusion is not justified by the data presented by Thornley et al. [Note: Our letter did not have a formal abstract; this summary was added for the preprint.]

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Very Local Subsidence Near the Hot Spring Region in Hakone Volcano, Japan, Inferred from InSAR Time Series Analysis of ALOS/PALSAR Data

Remote Sensing ◽

10.3390/rs12172842 ◽

2020 ◽

Vol 12 (17) ◽

pp. 2842 ◽

Cited By ~ 1

Author(s):

Ryosuke Doke ◽

George Kikugawa ◽

Kazuhiro Itadera

Keyword(s):

Time Series ◽

Time Series Analysis ◽

Land Subsidence ◽

Hot Spring ◽

Surface Displacement ◽

Chloride Ions ◽

Hydrothermal Fluids ◽

Alos Palsar ◽

Hakone Volcano ◽

Series Analysis

Monitoring of surface displacement by satellite-based interferometric synthetic aperture radar (InSAR) analysis is an effective method for detecting land subsidence in areas where routes of leveling measurements are undeveloped, such as mountainous areas. In particular, InSAR-based monitoring around well-developed hot spring resorts, such as those in Japan, is useful for conserving hot spring resources. Hakone Volcano is one of the major hot spring resorts in Japan, and many hot spring wells have been developed in the Owakudani fumarole area, where a small phreatic eruption occurred in 2015. In this study, we performed an InSAR time series analysis using the small baseline subset (SBAS) method and ALOS/PALSAR scenes of the Hakone Volcano to monitor surface displacements around the volcano. The results of the SBAS-InSAR time series analysis show highly localized subsidence to the west of Owakudani from 2006–2011 when the ALOS/PALSAR satellite was operated. The area of subsidence was approximately 500 m in diameter, and the peak rate of subsidence was approximately 25 mm/year. Modeling using a point pressure source suggested that the subsidence was caused by a contraction at approximately 700 m above sea level (about 300 m below the ground surface). The rate of this contraction was estimated to be 1.04 × 104 m3/year. Hot spring water is collected from a nearby well at almost the same depth as the contraction source, and its main dissolved ion component is chloride ions, suggesting that the hydrothermal fluids are supplied from deep within the volcano. The land subsidence suggests that the fumarole activity is attenuating due to a decrease in the supply of hydrothermal fluids from deeper areas.

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