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Hochstetter Lecture

The Hochstetter Lecturer (named in honour of Ferdinand von Hochstetter - see below) is chosen annually by the Awards Subcommittee. He or she gives a lecture at GSNZ branches during the year on recently completed and largely unpublished findings, and must have a reputation as a good speaker. Send your 2015 nomination to the Awards committee now!

The 2014 Hochstetter Lecturer is Chris Bromley from GNS. Chris will be touring the country during the year (itinerary and lectures to be annouced). At University centres the Hochstetter and a Supplementary lecture are given.

About the speaker

Chris Bromley is a senior geothermal researcher and geophysical consultant at GNS Science (Wairakei), with 35 years of international experience, including resource assessments, geophysical exploration, and environmental studies of geothermal fields and mineral deposits in 8 countries.

 

 

 

Hochstetter Lecture

"New Zealand's renewable geothermal resources."

Abstract:

Renewable energy will be crucial for the long-term future of all mankind. In New Zealand, we are relatively fortunate, in that renewable geothermal energy is already a major contributor (18%) to base-load electricity supply and industrial direct heat demand. Decades of well-focussed applied research has given us a global technological advantage in developing and utilising all types of geothermal resources, through cost-effective and environmentally benign strategies. Gazing into the crystal ball, what additional future use could we make of our geothermal resources? Should we attempt to develop say 3 GW(e) of surplus cheap geothermal power in the hopes of exporting it to Australia by cable or fully electrifying our transport sector, or should we develop say 10 GW(th) of hot water resources to establish large district heating schemes and attract more energy intensive industry? To address these questions we need to be confident that our geothermal resource use will be sustainable, and utilisation won't cause unwanted adverse environmental effects, or detract from our significant geothermal tourism assets. This requires better calibrated simulation modelling of long-term reservoir behaviour, adaptive management to facilitate flexible injection and production strategies, and more-advanced monitoring of reservoir behaviour in order to inform the adaptive decision-making process. Boreholes provide data for 3D models of reservoir properties, and a means of directly monitoring various parameters of interest (eg. pressure, temperature, fluid chemistry). Geophysics monitoring and exploration (eg. gravity, resistivity, micro-earthquake activity, seismic velocity tomography, and ground deformation) offer more indirect information on resources. Integrated interpretation with geochemistry and hydrothermal alteration processes is the key to better conceptual understanding, improved simulation models of reservoir behaviour, and more astute reservoir management.

Supplementary Lecture (University centres)

"Science meets policy: geothermal deployment and conservation in the Taupo Volcanic Zone."

Abstract:

 Our research into monitoring of the environmental effects of geothermal resource utilisation in the Taupo Volcanic Zone has tested and reaffirmed the benefits of adaptive management of production and reinjection strategies. These strategies can minimise or mitigate some important potential effects on the local surface environment, including: induced seismicity, subsidence, hydrological changes to thermal features, and gas emissions. For example, an improved understanding of the mechanisms of induced seismicity, through monitoring, helps deal with this issue while still enhancing fracture permeability and thereby energy recovery. Subsidence anomalies often show associations with relatively-shallow, anomalously-compressible, porous formations. These have typically been weakened by hydrothermal alteration caused by boiling fluids in outflow structures. Brittle-ductile transition behaviour occurs across a wide range of temperatures and rock types, and settlement can increase over time due to non-linear stress-strain relationships such as clay yielding. To properly simulate these brittle-ductile deformation processes, fully inter-coupled Thermal-Hydraulic-Mechanical-Chemical modelling would be preferred, but history matching suffers from too many variables and a shortage of good subsurface data. Alternative and more pragmatic modelling approaches, that simplify the geothermal deformation process, have proven to be reasonably successful. Adaptive mitigation options such as targeted injection management to control pressure and temperature are becoming acceptable tools. At several geothermal fields, changes in reinjection strategy have also resulted in managed surface feature changes. At Rotorua, management of extraction and reinjection from domestic bores achieved a significant recovery in hot spring and geyser activity. Regulatory control occurs through policies and plans. These undergo a regular process of industry-wide review and improvement, which, when backed by research, address changes in environmental management, by relying on successful experience of the adaptive approach, backed by good monitoring, rather than blind adherence to the precautionary principle.

Itinerary  (for more details go here or use the email contacts)
Branch / CentreDate
Email contacts
AucklandTuesday 19th AugustEmail: j.eccles_at_auckland.ac.nz
WaikatoWednesday 20th AugustEmail: apittari_at_waikato.ac.nz
TaupoMonday 18th August
Email: p.white_at_gns.cri.nz
RotoruaTuesday 2nd September
 
Napier 
Wednesday 27th August
Email: m.broadbent_at_xtra.co.nz
Manawatu 
Tuesday 26th August

Email: J.A.Palmer_at_massey.ac.nz

Wellington Monday 8th September
Email: huw.horgan_at_vuw.ac.nz
Taranaki 
Monday 1st September
Email: susan_at_netmail.co.nz
NelsonTuesday 9th September
Email: mike.johnston_at_xtra.co.nz
Otago 
Thursday 11th September
Email: n.mortimer_at_gns.cri.nz
CanterburyWednesday 10th September
Email: catherine.reid_at_canterbury.ac.nz

       
         
           
      
 

 

 

      
    

 

About Hochstetter by Mike Johnston

Christian Gottlieb Ferdinand von Hochstetter (1829-1884)

Hochstetter was born in Esslingen in the Kingdom of Wrttemberg and joined the Austrian Geological Survey in 1853. Four years later he was appointed geologist on the Austrian frigate Novara that undertook a global scientific cruise. The Novara berthed in Auckland, then the capital of New Zealand, on 22 December 1858. At the request of the New Zealand Government and supported by the Auckland Provincial Council, Hochstetter, accompanied by Julius Haast and others, surveyed the Drury Coal Field to the south of the capital.

This was accomplished so successfully that the provincial council persuaded the commander of the Novara to allow Hochstetter to remain in New Zealand so that he could undertake further work in the province. Over the next five months Hochstetter and Haast, and a support team, visited much of southern part of Auckland Province, including the volcanic region and the gold diggings at Coromandel Harbour.

On completion of his Auckland mapping, Hochstetter was commissioned by the Nelson Provincial Council to report on the mineral wealth of the province. Hochstetter, accompanied by Haast, arrived in Nelson, after brief stops at New Plymouth and Wellington, on 4 August 1859. In Nelson, they examined Dun Mountain, and from which he collected and subsequently named dunite, the Aorere Gold Field and other places of interest. While Hochstetter visited the Wangapeka Gold Field in the west and Lake Roto-it, Haast geologically examined the eastern part of the province . Hochstetter left Nelson for Sydney on 1 October 1859, on the first leg of his return voyage to Europe.

His geological maps of Auckland and Nelson were the first of their kind in New Zealand.

A list of previous Hochstetter Lecturers can be found on the Awards page

Website editor's note: the "o" in Hochstetter definitely does not carry an umlaut ()