title: Risk analysis associated with flank failure from Putauaki, Bay of Plenty, New Zealand

authors: Hewitt, Dolan

subjects: volcanic landslides

abstract: Volcanoes are dynamic evolving structures, with life cycles that are punctuated by episodes of
flank instability. Putauaki (Mount Edgecumbe) is a stratovolcano located onshore in the Bay of
Plenty, New Zealand. The aim of this study was to assess the stability of Putauaki and analyse the risk associated with volcanic collapse. To achieve this objective, a multidisciplinary approach was used, incorporating geomorphological and geological mapping, rock mass classification,
laboratory testing to identify geotechnical properties of materials representative of the volcano,
stability modelling, and analysis of landslide run-out zones.
Putauaki comprises two predominant features including the larger and younger Main Cone (the
summit lying 820 m a.s.l., slope angles up to 36 ), and smaller and older Main Dome (the summit
lying 420 m a.s.l., slope angle of 24 ). Both features show little evidence of erosion or surface
water. Rock mass description defined six lithotechnical units including indurated andesite,
indurated dacite, scoriaceous andesite, altered andesite (all categorised as hard rocks), and block
and ash flow and Matahina Ignimbrite (both categorised as soft rocks). The uniaxial compressive
strength (UCS) of indurated andesite and indurated dacite was 60   4 MPa and 44.7   0.9 MPa
respectively, correlating with moderately strong rock. Discontinuities of the indurated units were
widely spaced, showed medium persistence and wide aperture, and were slightly weathered. Infill
comprised predominantly loosely packed, very strong, coarse gravel. UCS of scoriaceous andesite
and altered andesite was 25   5 MPa and 15   1 MPa respectively, allowing categorisation as very
weak rock. Discontinuities of scoriaceous andesite were widely spaced, showed high persistence
and wide aperture, and were moderately weathered. Discontinuities of the altered andesite were
moderately spaced, showed low persistence and wide aperture, and were highly weathered. Infill
of scoriaceous and altered andesite was loosely packed, moist, weak to very weak medium gravel.
The block and ash flow was a poorly sorted, loosely packed, sandy, gravely and cobble rich matrix
supported deposit. The Matahina Ignimbrite was a very weak, discontinuity-poor deposit. Shear
box testing indicated cohesion and friction angle of 0 MPa and 42.1  (block and ash flow) and 1.4
x 10-3 MPa and 41.7  (Matahina Ignimbrite) respectively. These values are similar to published
values. Correlation of each lithotechnical unit to its respective rock mass description site allowed
approximate boundaries of each unit to be mapped.
Each unit's mass strength was combined with measured bulk densities and incorporated into two
dimensional slope profiles using the stability modelling package GalenaTM. Ten slope profiles of
Putauaki were constructed. Failure surfaces for each slope profile were defined using the Bishop
simplified multiple analysis method. Four slope profiles showed the potential for small scale
failure (less than 0.1 km2 of material). The remaining six slope profiles showed the potential for large
scale failure (greater than 0.1 km2 of material). Stability of these six slope profiles was investigated further
in relation to earthquake force, watertable elevation, and a disturbance factor of the rock mass (D).
Conditions of failure graphs for profile 6a showed that at low D (less than 0.4), earthquake forces and
watertable elevation must be unrealistically high for the region (greater than 0.33 g; greater than 15% watertable
elevation) in order produce a factor of safety less than 1. The remaining five slope profiles showed
potential to be unstable under realistic earthquake forces and watertable elevations. Two of these
profiles were unable to achieve stability at D greater than 0.8 (profile 4) and D greater than 0.9 (profile 5). A D value
of 0.6 (intermediate between 0.4 and 0.8) is argued to most realistically represent Putauaki. The
fact that Putauaki has not undergone large scale failure to date supports the conclusion that the
constructed models overestimate the influence of those factors which promote slope instability.
Maximum and minimum landslide run-out zones were constructed for the slope profiles exhibiting
the potential for large scale failure. Definition of the position and extent of maximum and
minimum run-out zones assumed H/L (fall height to run-out length) ratios of 0.09 and 0.18
respectively, as well as the 'credible flow path' concept. Identified impacts of landslides sourced
from Putauaki include inundation of Kawerau Township, Tarawera River, forestry operations, road
networks, and power supplies. Based on these impacts, the risk posed by landslides from each
slope profile was categorised as ranging from relatively low to relatively high. Landslides sourced from the south-west flanks pose a relatively low risk due to their prerequisite of unrealistically
high watertable elevations and earthquake forces. Landslides sourced from the north-west flanks pose a relatively high risk as minimum run-out will inundate north-east parts of Kawerau
Township. Landslides sourced from the eastern flanks pose a moderate risk due to their run-out
zones avoiding Kawerau Township.

text: Risk analysis associated with flank failure from Putauaki, Bay of Plenty, New Zealand Volcanoes are dynamic evolving structures, with life cycles that are punctuated by episodes of
flank instability. Putauaki (Mount Edgecumbe) is a stratovolcano located onshore in the Bay of
Plenty, New Zealand. The aim of this study was to assess the stability of Putauaki and analyse the risk associated with volcanic collapse. To achieve this objective, a multidisciplinary approach was used, incorporating geomorphological and geological mapping, rock mass classification,
laboratory testing to identify geotechnical properties of materials representative of the volcano,
stability modelling, and analysis of landslide run-out zones.
Putauaki comprises two predominant features including the larger and younger Main Cone (the
summit lying 820 m a.s.l., slope angles up to 36 ), and smaller and older Main Dome (the summit
lying 420 m a.s.l., slope angle of 24 ). Both features show little evidence of erosion or surface
water. Rock mass description defined six lithotechnical units including indurated andesite,
indurated dacite, scoriaceous andesite, altered andesite (all categorised as hard rocks), and block
and ash flow and Matahina Ignimbrite (both categorised as soft rocks). The uniaxial compressive
strength (UCS) of indurated andesite and indurated dacite was 60   4 MPa and 44.7   0.9 MPa
respectively, correlating with moderately strong rock. Discontinuities of the indurated units were
widely spaced, showed medium persistence and wide aperture, and were slightly weathered. Infill
comprised predominantly loosely packed, very strong, coarse gravel. UCS of scoriaceous andesite
and altered andesite was 25   5 MPa and 15   1 MPa respectively, allowing categorisation as very
weak rock. Discontinuities of scoriaceous andesite were widely spaced, showed high persistence
and wide aperture, and were moderately weathered. Discontinuities of the altered andesite were
moderately spaced, showed low persistence and wide aperture, and were highly weathered. Infill
of scoriaceous and altered andesite was loosely packed, moist, weak to very weak medium gravel.
The block and ash flow was a poorly sorted, loosely packed, sandy, gravely and cobble rich matrix
supported deposit. The Matahina Ignimbrite was a very weak, discontinuity-poor deposit. Shear
box testing indicated cohesion and friction angle of 0 MPa and 42.1  (block and ash flow) and 1.4
x 10-3 MPa and 41.7  (Matahina Ignimbrite) respectively. These values are similar to published
values. Correlation of each lithotechnical unit to its respective rock mass description site allowed
approximate boundaries of each unit to be mapped.
Each unit's mass strength was combined with measured bulk densities and incorporated into two
dimensional slope profiles using the stability modelling package GalenaTM. Ten slope profiles of
Putauaki were constructed. Failure surfaces for each slope profile were defined using the Bishop
simplified multiple analysis method. Four slope profiles showed the potential for small scale
failure (less than 0.1 km2 of material). The remaining six slope profiles showed the potential for large
scale failure (greater than 0.1 km2 of material). Stability of these six slope profiles was investigated further
in relation to earthquake force, watertable elevation, and a disturbance factor of the rock mass (D).
Conditions of failure graphs for profile 6a showed that at low D (less than 0.4), earthquake forces and
watertable elevation must be unrealistically high for the region (greater than 0.33 g; greater than 15% watertable
elevation) in order produce a factor of safety less than 1. The remaining five slope profiles showed
potential to be unstable under realistic earthquake forces and watertable elevations. Two of these
profiles were unable to achieve stability at D greater than 0.8 (profile 4) and D greater than 0.9 (profile 5). A D value
of 0.6 (intermediate between 0.4 and 0.8) is argued to most realistically represent Putauaki. The
fact that Putauaki has not undergone large scale failure to date supports the conclusion that the
constructed models overestimate the influence of those factors which promote slope instability.
Maximum and minimum landslide run-out zones were constructed for the slope profiles exhibiting
the potential for large scale failure. Definition of the position and extent of maximum and
minimum run-out zones assumed H/L (fall height to run-out length) ratios of 0.09 and 0.18
respectively, as well as the 'credible flow path' concept. Identified impacts of landslides sourced
from Putauaki include inundation of Kawerau Township, Tarawera River, forestry operations, road
networks, and power supplies. Based on these impacts, the risk posed by landslides from each
slope profile was categorised as ranging from relatively low to relatively high. Landslides sourced from the south-west flanks pose a relatively low risk due to their prerequisite of unrealistically
high watertable elevations and earthquake forces. Landslides sourced from the north-west flanks pose a relatively high risk as minimum run-out will inundate north-east parts of Kawerau
Township. Landslides sourced from the eastern flanks pose a moderate risk due to their run-out
zones avoiding Kawerau Township.

year: 2007

title: Spectroscopic and synthetic studies of lichen metabolites

authors: Ronaldson, Kathlyn Joy

abstract: Lichen metabolites from various Nephroma and Pseudocyphellaria species have been subjected to a number of spectroscopic and synthetic investigations. Hypoiodite reaction of 15α-acetoxyhopan-17(21)-en-24-ol yielded a complex mixture of products, while similar reaction of 7-oxohopan-22-ol resulted in cleavage of the side-chain. Preparation of an α-sulphenylated 15-ketone was achieved as the first step in a carbonyl transposition sequence. Complete assignment of the ¹³C nmr spectra of four pentacyclic and two ring A-cleaved stictane derivatives provided evidence of the boat-ring B. The low frequency infrared spectra of a number of stictane and hopane triterpenoids yielded structurally significant correlations. Two depsidonal constituents of N. australe were demonstrated to be hypostictic acid and hyposalazinic acid. The reactions of mercuric acetate with unsaturated compounds are reviewed and anomalous products of Jones reagent oxidation investigated.

text: Spectroscopic and synthetic studies of lichen metabolites Lichen metabolites from various Nephroma and Pseudocyphellaria species have been subjected to a number of spectroscopic and synthetic investigations. Hypoiodite reaction of 15α-acetoxyhopan-17(21)-en-24-ol yielded a complex mixture of products, while similar reaction of 7-oxohopan-22-ol resulted in cleavage of the side-chain. Preparation of an α-sulphenylated 15-ketone was achieved as the first step in a carbonyl transposition sequence. Complete assignment of the ¹³C nmr spectra of four pentacyclic and two ring A-cleaved stictane derivatives provided evidence of the boat-ring B. The low frequency infrared spectra of a number of stictane and hopane triterpenoids yielded structurally significant correlations. Two depsidonal constituents of N. australe were demonstrated to be hypostictic acid and hyposalazinic acid. The reactions of mercuric acetate with unsaturated compounds are reviewed and anomalous products of Jones reagent oxidation investigated.

year: 1980

title: Mā te hangarau te oranga o te reo Māori e tautoko ai? Can technology support the long-term health of the Māori language?

authors: Mato, Paora James

subjects: Te reo Māori

abstract: Can contemporary technologies be used to support the ongoing health of an endangered language? Since the late twentieth century unprecedented and substantial social changes have been propelled by advances in contemporary technologies. Continuous connectivity harnessing digital communication, mass media and social networking has enabled instant diffusions of ideas, viewpoints and values. Unrestrained broadcasting and publishing by the general populace and the absence of the traditional media gatekeepers has been linked to the weakening of traditional cultural and linguistic ties as the private, more intimate oral domains inherent to minority indigenous cultures are being opened up to more public modes of consumption. Additionally, significant numbers of minority language speakers switch from the use of their own languages in digital environments to a language that is globally more recognisable. This type of digital language switching emulates the historical occurrence of language shift as minority language speakers opt to use a language that they perceive to be of more benefit to themselves and to their children.

Ironically, language revitalisation initiatives are embracing the ubiquitous attributes of digital technology. A joint venture between the Microsoft Corporation and the University of Waikato resulted in Māori-language interfaces for Microsoft Office and Windows. These and similar interfaces for a range of other applications were investigated. The testing groups were largely unaware the translated interfaces existed and expressed pleasure and pride to see te reo Māori within the various technologies. Following engagement the feedback was less positive. New words, unfamiliar uses of words and poor translations were cited as significant difficulties. Ensuing navigation was often hesitant and uncertain. Were the translations unsuitable? Is te reo Māori unusable within these technologies? The high incidence of task completion suggests difficulties may have arisen from a previous competence with the technologies in another language - English in this case. Future initiatives would do well to consider that perceived difficulties might arise from factors other than the design of the interfaces themselves.

 
Te reo Māori is being used on Twitter. Particular events significantly impacted the use of tweeting in te reo. During Māori Language Week the number of tweeters increased. During the Matatini Festival the volume of tweets increased. While creating an online Māori-language community, a range of strategies became necessary to maintain and prolong some conversations. At times, bilingual tweets extended faltering conversations. Sometimes forwarding tweets drew success. Furthermore, a significant number of people preferred to watch without engaging directly – perhaps a target area for future strategies.

Te reo Māori is a viable option within various technologies as evidenced by the increasing use of the language on a range of contemporary platforms. Translated interfaces provide opportunities for language promotion and extensive language visibility. The development of an online language forum has shown that conversations in te reo Māori can be successfully fostered using social media. Understanding the differences between the static visibility of translated interfaces and the dynamic nature of online conversations can be a huge asset for language strategies once issues of awareness, perception and extended engagement are successfully addressed.

text: Mā te hangarau te oranga o te reo Māori e tautoko ai? Can technology support the long-term health of the Māori language? Can contemporary technologies be used to support the ongoing health of an endangered language? Since the late twentieth century unprecedented and substantial social changes have been propelled by advances in contemporary technologies. Continuous connectivity harnessing digital communication, mass media and social networking has enabled instant diffusions of ideas, viewpoints and values. Unrestrained broadcasting and publishing by the general populace and the absence of the traditional media gatekeepers has been linked to the weakening of traditional cultural and linguistic ties as the private, more intimate oral domains inherent to minority indigenous cultures are being opened up to more public modes of consumption. Additionally, significant numbers of minority language speakers switch from the use of their own languages in digital environments to a language that is globally more recognisable. This type of digital language switching emulates the historical occurrence of language shift as minority language speakers opt to use a language that they perceive to be of more benefit to themselves and to their children.

Ironically, language revitalisation initiatives are embracing the ubiquitous attributes of digital technology. A joint venture between the Microsoft Corporation and the University of Waikato resulted in Māori-language interfaces for Microsoft Office and Windows. These and similar interfaces for a range of other applications were investigated. The testing groups were largely unaware the translated interfaces existed and expressed pleasure and pride to see te reo Māori within the various technologies. Following engagement the feedback was less positive. New words, unfamiliar uses of words and poor translations were cited as significant difficulties. Ensuing navigation was often hesitant and uncertain. Were the translations unsuitable? Is te reo Māori unusable within these technologies? The high incidence of task completion suggests difficulties may have arisen from a previous competence with the technologies in another language - English in this case. Future initiatives would do well to consider that perceived difficulties might arise from factors other than the design of the interfaces themselves.

 
Te reo Māori is being used on Twitter. Particular events significantly impacted the use of tweeting in te reo. During Māori Language Week the number of tweeters increased. During the Matatini Festival the volume of tweets increased. While creating an online Māori-language community, a range of strategies became necessary to maintain and prolong some conversations. At times, bilingual tweets extended faltering conversations. Sometimes forwarding tweets drew success. Furthermore, a significant number of people preferred to watch without engaging directly – perhaps a target area for future strategies.

Te reo Māori is a viable option within various technologies as evidenced by the increasing use of the language on a range of contemporary platforms. Translated interfaces provide opportunities for language promotion and extensive language visibility. The development of an online language forum has shown that conversations in te reo Māori can be successfully fostered using social media. Understanding the differences between the static visibility of translated interfaces and the dynamic nature of online conversations can be a huge asset for language strategies once issues of awareness, perception and extended engagement are successfully addressed.

year: 2018