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Citizen Science and the University of Queensland Seis-Mo-Graph Stations (UQSS) – A Study of Seismic T Waves in S-W Pacific Ocean
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24 May 2023
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25 May 2023
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Abstract
Abstract: This paper summarises an early and successful piece of citizen science, performed within The University of Queensland Seismograph Stations (UQSS) observatory, in cooperation with colleagues at CSIRO. It was designed to en-courage young STEM students from Brisbane high schools to engage in “real” re-search, back in 1995. Having completed the project report, their (analog) results sat in a cupboard until the report was dusted off and the project was re-analysed in 2022 by an honors student, considering timely climate change applications for the study. This is a time when science is changing considerably from analog to digital medium and operational methods.
The original project was called Earthquake generated T phases on BRS Seismograph (Brisbane, Q’ld)- a predictor for Tasman Sea Tsunamis? [1] Fortunately, seismology is a very collaborative field. The research question has since changed. There is a lot of data analysis involved in the science of recording earthquake signals, with auxiliary definitive catalogues, observers logbooks, housing of the recordings themselves (analog and digital) and the software mediums that change over time. In other words, a lot of headaches can be encountered in longitudinal data collection study such as this. The citizen science students used a pre-prepared decadal collection (1980-90) derived from the BRS observatory data catalogue. BRS is part of the global World-Wide Seismograph Station Network (WWSSN).
Currently in Australia, university earth science observatories have diminished, and in their place, public seismic networks (PSN) have evolved, either in back-yard sheds or school science labs. The level of expertise required fits the role of advancing citizen science for a real science advantage. This is a topical citizen disaster preparedness action area for today’s climate emergency, which is threatening the globe and all lifeforms. Citizen engagement or mobilisation is an essential preparedness strategy.
Keywords: citizen science 1; seismology 2; earth observation 3; climate change 4; education for sustainable development 5; disaster preparedness 6; disaster alerts 7
Keywords:
Subject: Environmental and Earth Sciences - Geophysics and Geology
1. Introduction
This story begins in 1995 and it concludes with a successful joint CSIRO Double Helix student research project with The University of Queensland Seismograph Stations (UQSS). The data and findings were tantalising and were archived. In 2021, the authors resurrected the data and began working with a larger digital earthquake database (ISC). This now raised the larger research question of: Would climate change effects in the oceans change the transmission velocity of earthquake T waves? If so, how could T waves, be used to measure climate change?
This paper exemplifies the application of education for sustainable development (ESD)? This is UNESCO’s education sector’s response to the urgent and dramatic challenges that the planet faces. The collective activities of human beings have so altered the earth’s ecosystems that our very survival seems in danger because reparation strategies become more difficult to reverse every day. To contain global warming before it reaches catastrophic levels means addressing environmental, social, and economic issues in a holistic way [2].
In Europe, implementation of the citizen science connection recognizes that “It is thus crucial to train the (local and national) population enabling them to increase their preparedness for disasters and, consequently, improve society’s resilience.” The European-Mediterranean Seismological Centre (EWSC) operates a global social media earthquake reporting system called @LastQuake [3].
In the USA, we see the implementation of “ShakeAlert” that utilises the sensors in a mobile phone to both detect earthquakes (if enabled by the citizen owner) and also, give an early advance warning to threatened populations. [4].
In Australia, the first major government sponsored citizen science seismology research was the Australian Seismometers in Schools program [5], which was initially a four-year project (2011-2014) funded by the Geophysical Education Observatory component of AuScope Australian Geophysical Observing System (AGOS) funded by the Federal Government, under the Education Infrastructure Scheme. It is still operating today. The Auscope main page can be found at www.auscope.org.au. Another university based seismic monitoring exists at the Centre for Geomechanics (UWA) which was set up as a “public seismic network” [6].
More recently, the reverse is happening within universities. With post-Covid downsizing of universities and the casualisation of academic staff contributing to a knowledge malaise in the earth science and environmental teaching and research sector, there is now a paucity of extension projects to manage citizen science. This is indicative of systems not recovering from a major threat to their routines.
Australian Learned Societies would seem to be the only long-term operating platforms utilising naturalist volunteer activity. There are existing citizen organised “public seismic networks”. Citizen scientists run the Seismological Association of Australia [7] which has an active instrument array in South Australia. Professional organisations such as Engineers Australia seem disinterested in engaging with volunteer citizen science, most probably because they have strict membership codes.
Raspberry Shake is globally growing commercial program appealing to amateur Australian citizens and teachers. Their stated mission is to “become the largest publicly available streaming seismic network in every country” [8]. The commercial venture proves the interest of citizens becoming amateur seismologists.
In 1995, two Brisbane Year 12 high school students investigated this UQSS study - believed to be the first of its kind in Australia using earthquake sound waves to predict tsunamigenic areas in the Tasman Sea affecting eastern Australia. Ms. Lahey and Mr. Karunaratne chose the seismology project from among topics listed with the CSIRO Student Research Scheme, a national program which allows selected senior secondary students to participate in small-scale research projects supervised by practicing scientists in research laboratories.
In 1995 Mr. Lynam (UQ Earth Sciences Senior Technical Officer) said the “University was happy to participate in the scheme to arouse the students’ scientific research skills and foster the inquisitive excitement necessary for the potential scientists of tomorrow.” He said the project also gave the students exposure to The University of Queensland’s role as part of a world-wide earthquake monitoring network which has been operating since 1937. The UQSS recorded earthquakes on its two World Wide Standard Station Network (WWSSN) observatories located at Charters Towers (CTAO) and Mt Nebo (BRSA) in a globally co-operative venture with the U.S. Coastal and Geodetic Survey, the U.S. National Disaster Centre, and the Australian Seismological Centre (now Geosciences Australia). More recently the global supervisory role of CTBTO operates the global network whose chief focus is as a nuclear detection International Monitoring System and deterrent.
Observations of the Tasman Sea T (tertiary) wave occurrences were made routinely by observors at The UQSS (now defunct ~2005). They are one of nature’s fractal measurement oddities, because their complexity changes with the measurement scale used. T waves are simply described as acoustic wave energy, travelling in the Sofar layer of oceans (~1 km depth). This oceanic phenomenon is an inversion layer interfaced by temperature, salinity, and pressure. T waves are observed in acoustic ocean bottom sensors (OBS) or on land-based seismograph recorders. Marine mammals also communicate in this ocean inversion layer medium. Its low attenuation properties transmit sound for 10,000 km or more.
These T waves occur when a massive subduction fault movement generates earthquake energy which radiates out as seismic P waves through the earth’s inner geological structures. Sometimes (depending on refraction), such impinging seismic P waves will strike the interface between the sloping continental shelf and ocean. The refracted energy will “leak” from many points along that wavefront into a specific ocean inversion layer - the Sofar inversion layer (~1 km depth). This energy will transmit as an acoustic sound, unattenuated, and arrive at another continental slope, refracting itself, at the correct angle, into an earthquake P wave again. Hence, the multi refractions and mediums give rise to complex transformation algorithms that must account for temperature, salinity, geophysics, oceanography, thermometry, and possibly climate change.
Should you live nearby an impinging T wave train, you may experience what you thought was a nearby earthquake [9]. Similar “sound” inversions happen in the air above oceans and are reported as “Barisal guns”. Nature is indeed both fascinating and kind to seismologists.
The UQSS pilot study initially included analysis of previously recorded earthquake T wave data and correlation with aberrations registered on tide gauges. While checking tide records held in the Queensland Department of Transport Tidal Records section, Mr. Lynam and the students coincidentally discovered a link between an Indonesian earthquake and a tsunami affecting a tide gauge in Weipa (Cape York). The T wave data however could not be conclusively associated with tide gauge recordings of earthquake generated tsunami. This was a “null” outcome for an old theory.
The surprise outcome of the citizen science project was the collection, mapping and realisation of the travel path and velocity of T waves in the Tasman Sea. This was indeed a unique suite of geophysical data that linked subduction earthquakes and their crustal noise (land path), to a leakage transmission of energy through oceans (water path), then refracting back into a land path on continental shelves. The geographic location makes this pilot study unique in the S.W Pacific geophysics. New research is also added to fascinate the reader. No conclusions are arrived at - only more potential research questions.
2. Materials and Methods
2.1. Citizen science influences of the UQSS
Citizen science reporting has been an essential feature of the operation of the UQSS, since as far back as 1953 [9] when the then Director of UQSS, the late Dr Owen Jones and UQSS technician, Mr. A Crawfoot, built a home-made seismograph at Crawfoot’s house in Woody Point. They encouraged other “amateur seismologists” to join them and collect seismograph data for the global seismology community [10]
Even the daily UQSS observatory routine practice of collecting “felt report” data about the irregular local earthquake events, required descriptive responses from the general public who replied to mailed out Modified Mercalli questionnaire requests for felt experiences in an earthquake. Five to ten of these surveys might have been conducted each year. This macro data supplemented the lack of instrumental data [11]. In recent times, seismology is able to interface directly with the public and their electronic media usage.
2.2. Seismograph observatory practice for data collection
The observational data used by these UQSS/CSIRO students was derived from the daily seismograms and observational bulletins, created by fulltime observors. The daily routine for seismological observors is to take the seismograms from the previous 24 hours and accurately:
- ○
- annotate the 6 charts (short period Z, N-S, E-W and long period Z, N-S, E-W) with their unique descriptors.
- ○
- provide station name, date/time ON-OFF; sensor direction; clocking error.
- ○
- methodically and chronologically pic timed events (blast. earthquake, local noise, microseism noise level) into the observors daily log of seismic phases, onset strength and direction and comments.
- ○
- telex the day logs of observed earthquake phase times and descriptors to the United States Geological Survey and Geosciences Australia (then BMR or AGSO), and then compile them into a weekly station bulletin publication. This was faxed to global agencies who compiled definitive catalogues of earthquake epicentres e.g., ISC, USGS and GA, as well as the UQSS archives [12].
When the UQSS earthquake monitoring began in 1937 (UQ, Gardens Point, Brisbane) [13] all of this observational interpretation was analog, handwritten, and teletype transmitted. In about 1973-74, the UQSS was able to digitally store observations onto the central computing facility at the UQ Prentice Centre. Thus, rapid digital searching of data became possible. The advent of programable computers made this process more flexible and data re-use friendly. Prior to that observer’s earthquake phase data was typed into weekly “bulletins” and paper versions of these were bound into catalogued books.
The seismology observor makes observations about “squiggles” on the charts that may have been generated by local or teleseismic earthquakes, explosions, or nuclear blasts. These point sources (epicentres) send seismic/sound energy in radial directions, and the waveforms are transmitted quickly (3 km/s to 8 km/s) through the geological formations or through the oceans (~1.5 km/s) or even into the ionosphere (infrasonically). The observer will note impulsive or emergent onsets at the date-time of the arriving P phase and then the later arriving (S phase) and maybe the more damaging surface waves (L, R phases). There are a multitude of refracted wave types recorded.
The rationale for running the first and longest Australian university continuous seismograph observatories at The University of Queensland is best described by the late Dr Jack Webb (Director UQSS) in Cooperation and the UQ Seismograph Stations [14].
2.3. Brief review of (BRS) T wave historical research literature
Prior to the inception of this CSIRO project, the UQSS observors had become aware of a strange new type of phase (T phase) with a characteristic signature and much later arrival. The observor learnt from colleagues that these T waves travelled (earth > ocean SOFAR layer > earth) and were usually detected by observatories near the ocean. The first scientific reference to the T wave is attributed to Linehan [15] (Figure 1) who documented their arrival on Caribbean seismograms, shown in Figure 1.
A study of more than 200 records of T from the Atlantic 7 has shown that in all cases the period ranges upward rather than downward from 0.5 sec., being for the most part between 0.5 and 1.0. This is significant, because SOFAR propagation (SOFAR stands for sound fixing and ranging) along an axis of minimum velocity cannot explain transmission of waves of periods longer than 0.5 sec. carrying the greater part of the energy in T. T does not travel with the velocity of sound in water for the part of its path crossing deep water. Its oceanic velocity ranges from 1.70 km/sec to 2.65 km/sec, in different parts of the Atlantic (5,577 to 8,695 ft/sec.), in contrast to • velocities of sound in water from 1.46 to 1.53 km/sec. (4,790 to 5,020 ft/sec.). Its speed over land paths is 2.13 km/sec. (6,988 ft/sec.) [15].
Another observation at BRS (Gardens Point) occurred on 23-09-1949 (Table 1) when an event was recorded on the BRS Benioff Z (short period) sensor recorder. This event was reported to the Smithsonian Institute for Short Lived Phenomena and was later picked up by researchers as a T wave generated by the Queen Charlette Islands earthquake (Canada) and reported in a research paper [16] (Figure 2). This is an incredible distance for sound to travel in an ocean.
2.4. Reviewing recent research literature about the research relevance of T waves
- Why Research “T” waves?
“Nevertheless, recording T waves in the oceans has far-reaching utility for seismic studies and beyond, including tracking icebergs [17] monitoring submarine volcanic eruptions [18] and Comprehensive Nuclear Test-Ban Treaty verification [19]. Most recently, Wu et al. [20] demonstrated that decadal-scale ocean-warming trends are manifest in the differences in travel-time delays between T waves generated by repeating earthquakes” [21]
- New techniques linking seismology to oceanography;
“The deployment of around 4,000 autonomous devices called Argo floats that capture temperature information has helped enormously, but there are big gaps in our knowledge. This is especially true in relation to what’s happening in the waters deeper than 2,000 m. But now a team of researchers has developed a very different approach that exploits the fact that the speed of sound in seawater depends on temperature. The idea was first proposed and trialled in the late 1970s using sound waves generated by scientists. However, concerns over the impact of these sounds on marine mammals and rising costs saw the idea abandoned.” [22]
- Are T waves a tsunami predictor;
“T” Phases and tsunami waves can be generated by earthquakes simultaneously, or NOT, and so “T” wave detection on ocean bottom sensors (OBS) or floating sonar buoys or land-based seismographs are not an early warning indicator.
- Mechanism and fault relationship;
“These “T” phase arrivals can be observed in seismograms from receivers on land. Although most often recognised at coastal stations (or hydrophones), T phases can have large continental paths on the receiver end and have been observed at land stations several hundred kilometres away from the coast.” [23]
“The mechanism of coupling from acoustic waves to seismic waves is not clear but has been proposed to be related to the slope of the seafloor near the shore, and the contrast.”
“The T phase does not depend only on the earthquakes’ magnitude, but also on the depth where earthquakes occur, the continental slope, the conversion location, and the conversion efficiency” [24]
- T waves are a disaster hazard;
T waves retransmit back into seismic P waves and can cause felt effects in structures [8], (or cause submarine landslides).
- Thermometry and bathymetry;
Predicting the travel-time changes from the temperature anomalies estimated by ECCO. The speed with which the sound travels is governed by the depth, the salinity, and the water temperature. Consequently, experiments have been proposed and executed to actively monitor the ocean temperature under global warming with hydro-acoustic observations [25].
- This so-called acoustic thermometry;
is based on the efficient propagation through the SOFAR channel and uses the above-mentioned dependence of the sound speed on the temperature.
- ○
- Diurnal variations in the SOFAR channel were found by analysing the travel time differences from the source to the receivers.
- ○
- From this, propagation in the Atlantic appeared to vary strongly between the north and south Atlantic Oceans, which is further studied in Section 4 The celerity approach and findings are evaluated in Section 5, where also opportunities for future research are identified. The conclusions from this study are drawn in Section 5 [25].
2.5. Student (citizen science) project
In 1995, the student project was believed to be the first of its kind in Australia, using earthquake sound waves derived from the tsunamigenic areas in the Tasman Sea affecting eastern Australia. University lecturer in exploration geophysics, Dr Steve Hearn was supervising the study by Ms. Bronwyn Lahey, of Brisbane Girls Grammar School, and Mr. Asanka Karunaratne, of Brisbane State High School.
They set out to study the link between tsunamis (commonly but incorrectly called tidal waves) and submarine earthquakes. Dr Hearn said when an earthquake occurred below continental slopes, it generated a number of different sound waves, including a packet of energy known as a T-wave, which travelled more slowly (1.5 km/sec) and arrived later than other sound waves.
“An earthquake originating off Fiji might generate a fast-travelling P-sound wave, which would travel through the earth at 6 km/sec and be recorded in Australia 10 minutes later,” he said.
“A T-wave generated by the same earthquake would travel more slowly through water (at l.5 km/sec) and be recorded on seismographs in Australia about 30 minutes after the event. Scientists in Australia have devoted most of their attention to the faster-travelling sound waves to record earthquakes, but at The University of Queensland we are now looking at the slower T-wave as a predictive tool for tsunamis - While these kinds of studies have been undertaken elsewhere in the world, including at Hawaii and Japan, it is a relatively new research field for Australia. The exploratory work these students are undertaking will greatly assist more detailed studies which we hope can be achieved with competitive research funding.”
More recently, we have become aware of the relationship that T waves have with ocean heat waves, as outlined in Section 2.4
Seismograph station senior technician in the university’s Earth Sciences Department. Mr. Col Lynam said, “At sea, tsunamis were very small - only one third to half a metre high - but they had enormous wavelengths which could be up to 200 km long. As the wave reached the shore the wave crest(s) build up rapidly and could rise 30 m in 10 to 15 minutes, with devastating results.”
3. Results
The students began by analysing all BRS observatory daily earthquake “pics”, for the period of 1980 to 1990. These had been digitised for BRS seismogram bulletins in the mid-1980’s with the assistance of the Prentice Computer Centre at UQ. Observors conducted a search of the digital BRS seismology bulletins for all observed earthquake P phase arrival times that had associated T phase arrival times, dates and times and observations. This yielded 68 earthquake T wave events. These are tabulated in Table 2.
Having tabulated those events, the students then commenced searching for confirming epicentre origin times and descriptors, using definitive catalogues published by USGS. and ISC [26]. They produced Table 3, which defined the source locations and depth, magnitude and azimuth of the T wave generating earthquakes together with the velocities and the wave path(s) in the Tasman Sea area of the S-W Pacific Ocean. No consistent relationship with known tsunami events was discovered, so it was decided that result nullified the T wave <> Tsunami relationship.
3.1. Student T wave data collection and epicentre location analysis results
The student analysis data is tabulated and mapped below, showing the earthquake epicentres that caused a T wave to be generated and detected on the BRS seismograph. What becomes evident from their the analysis (Figure 4) is;
- Not all earthquakes generate T waves
- T waves originate from only certain tectonic zones (some misnamed?)
- There is a wide variation in T wave travel velocity
- There does appear to be a seasonality in T wave reception by BRS
- There is a paucity of T waves passing across the submerged Zealandia continent
- T wave paths also plot clear paths for tsunami hazard along east coast of Australia [27]
Table 2.
Student T wave data epicentre location analysis - arranged in location clusters.
| DATE | TME_REC (utc) | LOCATION | LAT (S) | LONG (E) | DEPTH (Km) | AZMUTH | MS | MB |
|---|---|---|---|---|---|---|---|---|
| 25/05/1981 | 11:09:40 | AUCKLAND ISLANDS | 49.41 | 164.28 | 12 | 334 | 5.1 | |
| 25/05/1981 | 11:30:10 | AUCKLAND ISLANDS | 49.35 | 164.58 | 19 | 333 | 4.6 | |
| 25/05/1981 | 14:18:10 | AUCKLAND ISLANDS | 49.34 | 164.27 | 33 | 334 | 4.3 | |
| 25/05/1981 | 20:07:10 | AUCKLAND ISLANDS | 49.35 | 164.28 | 33 | 334 | 4.4 | |
| 25/05/1981 | 22:23:05 | AUCKLAND ISLANDS | 49.28 | 164.23 | 33 | 334 | 4.5 | |
| 28/05/1981 | 0:48:00 | AUCKLAND ISLANDS | 49.5 | 163.88 | 33 | 335 | 4.3 | |
| 28/05/1981 | 05:52:00 | AUCKLAND ISLANDS | 49.13 | 164.43 | 12 | 333 | 4.9 | |
| 30/05/1981 | 09:12:28 | AUCKLAND ISLANDS | 49.14 | 164.63 | 333 | 5.3 | 5.8 | |
| 31/05/1981 | 08:24:00 | AUCKLAND ISLANDS | 49.82 | 164.1 | 33 | 335 | 4.2 | |
| 16/06/1981 | 16:29:45 | AUCKLAND ISLANDS | 49.07 | 164.79 | 33 | 332 | 5.3 | |
| 6/08/1981 | 11:52:20 | AUCKLAND ISLANDS | 49.76 | 163.96 | 33 | 335 | 4.6 | |
| 16/08/1981 | 05:41:45 | AUCKLAND ISLANDS | 49.54 | 164.32 | 33 | 334 | 4.5 | |
| 22/04/1986 | 22:19:23 | AUCKLAND ISLANDS | 49.96 | 163.69 | 10 | 336 | 4.8 | |
| 3/05/1987 | 12:52:33 | AUCKLAND ISLANDS | 49.17 | 164.6 | 13 | 333 | 5.3 | 4.6 |
| 20/12/1988 | 14:20:10 | AUCKLAND ISLANDS | 50.5 | 163.1 | 10 | 4.7 | 4.8 | |
| 26/10/1989 | 03:09:00 | AUCKLAND ISLANDS | 50.7 | 162.8 | 10 | 4.7 | 4.4 | |
| 21/11/1989 | 15:03:21 | AUCKLAND ISLANDS | 50.18 | 162.6 | 10 | 5.8 | 5.6 | |
| 23/02/1991 | 15:26:00 | AUCKLAND ISLANDS | 49.1 | 164.9 | 10 | 332 | 4.9 | |
| 17/09/1989 | 06:28:10 | BAL.LENY ISLAND | 61.4 | 154.1 | 10 | 5.6 | 5.4 | |
| 16/01/1980 | 04:17:50 | LOYALTY ISLANDS | 21.85 | 170.58 | 56 | 5.6 | 5.4 | |
| 6/07/1981 | 03:25:36 | LOYAL TY ISLANDS | 22.29 | 171.64 | 114 | 250 | 6.3 | |
| 6/09/1981 | 11:19:30 | LOYALTY ISLANDS | 21.5 | 169.61 | 36 | 246 | 6.0 | |
| 29/10/1981 | 12:23:47 | LOYAL TY ISLANDS | 23.65 | 169.11 | 18 | 252 | 5.1 | |
| 15/11/1984 | 03:03:22 | LOYALTY ISLANDS | 22 | 170.91 | 119 | 248 | 6.3 | |
| 15/01/1986 | 20:33:57 | LOYAL TY ISLANDS | 21.37 | 170.31 | 144 | 246 | 6.0 | |
| 1/05/1986 | 19:49:00 | LOYAL TY ISLANDS | 21.85 | 170.13 | 71 | 247 | 5.7 | |
| 31/07/1988 | 13:06:41 | LOYALTY ISLANDS | 22.26 | 171.02 | 85 | 5.7 | ||
| 21/09/1988 | 11:21:00 | LOYALTY ISLANDS | 22.27 | 170.97 | 88 | 5.1 | ||
| 17/02/1991 | 07:16:23 | LOYAL TY ISLANDS | 21.17 | 169.76 | 73 | 245 | 5.5 | |
| 31/12/1984 | 22:21:27 | MACCQUARIE ISLAND | 60.21 | 153.8 | 10 | 359 | 5.5 | 5.3 |
| 3/09/1987 | 00:07:17 | MACQUARIE ISLAND | 58.86 | 158.48 | 15 | 7.2 | 5.9 | |
| 15/11/1989 | 19:48:37 | MACCQUARIE ISLAND | 52.34 | 160.07 | 10 | 5.4 | 5.7 | |
| 17/09/1990 | 14:15:00 | MACCQUARIE ISLAND | 53.17 | 159.64 | 10 | 346 | 6.0 | 5.9 |
| 23/05/1984 | 00:05:44 | N OF MACQUARIE I | 51.88 | 161.08 | 10 | 342 | 5.8 | 5.8 |
| 18/09/1981 | 09:24:05 | NEW CALDONIA | 22.81 | 167.6 | 33 | 248 | 4.4 | |
| 17/12/1988 | 01:13:45 | NEW CALEDONIA | 26.93 | 167.53 | 25 | 5.3 | 5.5 | |
| 24/02/1991 | 09:52:00 | NEW CALEDONIA | 22.72 | 166.64 | 33 | 247 | 5.0 | 4.9 |
| 28/01/1980 | 12:55:10 | NEW ZEALAND | 45.26 | 167.5 | 118 | 5.1 | ||
| 26/07/1987 | 22:12:12 | NW OF NZ | 30.23 | 165.8 | 10 | 5.4 | 5.2 | |
| 25/05/1988 | 13:41:39 | NWOF NZ | 30.7 | 167.7 | 10 | 4.4 | 4.8 | |
| 27/09/1985 | 03:59:30 | SOLOMON ISL.ANDS | 9.81 | 165.85 | 33 | 200 | 6.8 | 6.2 |
| 30/08/1980 | 06:19:02 | SOUTH ISLAND NZ | 45.06 | 167.67 | 112 | 321 | 4.6 | |
| 27/05/1981 | 19:23:00 | SOUTH ISLAND NZ | 48.48 | 164.48 | 12 | 332 | 4.6 | |
| 22/11/1981 | 19:00:15 | SOUTH ISLAND NZ | 44.46 | 167.63 | 18 | 320 | ||
| 4/07/1982 | 16:05:00 | SOUTH ISLAND NZ | 10 | 320 | 4.7 | |||
| 27/09/1984 | 22:04:21 | SOUTH ISLAND NZ | 44.14 | 168.66 | 1 | 317 | 4.7 | |
| 12/09/1985 | 13:16:30 | SOUTH ISL.AND NZ | 45.4 | 167.36 | 80 | 322 | 5.1 | |
| 11/07/1986 | 17:20:05 | SOUTH ISLAND NZ | 44.54 | 167.45 | 12 | 321 | 4.2 | |
| 16/05/1988 | 10:19:00 | SOUTH ISLAND NZ | 44.17 | 168.13 | 12 | 4.2 | ||
| 3/06/1988 | 23:47:20 | SOUTH ISLAND NZ | 44.86 | 167.64 | 82 | 5.7 | ||
| 9/06/1988 | 12:33:30 | SOUTH ISLAND NZ | 44.99 | 167.48 | 65 | 4.2 | ||
| 14/06/1988 | 16:07:00 | SOUTH ISLAND NZ | 44.47 | 168.34 | 8 | 4.2 | ||
| 15/02/1991 | 11:12:16 | SOUTH ISLAND NZ | 42.08 | 171.59 | 8 | 308 | 5.0 | 5.8 |
| 28/05/1981 | 21:18:00 | VANUATU | 15.01 | 166.97 | 121 | 225 | 4.8 | |
| 6/04/1984 | 23:25:10 | VANUATU | 18.95 | 168.89 | 185 | 237 | 5.8 | |
| 16/07/1986 | 12:58:08 | VANUATU | 19.52 | 169.16 | 21 | 239 | 6.2 | |
| 12/08/1990 | 21:41:50 | VANUATU | 19.48 | 169.12 | 164 | 239 | 6.3 | |
| 15/06/1981 | 02:56:00 | W COAST, SIS NZ | 48.46 | 165.11 | 33 | 331 | 5.3 | 5.2 |
| 27/06/1981 | 22:04:00 | W COAST, SIS NZ | 48.8 | 164.2 | 33 | 333 | 4.4 | |
| 23/12/1981 | 15:24:00 | W COAST, SIS NZ | 47.74 | 165.77 | 10 | 329 | 3.8 | |
| 31/01/1985 | 04:56:00 | W COAST, SIS NZ | 46.01 | 165.16 | 10 | 328 | 6.0 | 5.8 |
| 21/09/1985 | 14:14:26 | W COAST, SIS NZ | 46.37 | 165.78 | 22 | 327 | 4.9 | |
| 3/04/1986 | 14:33:22 | W COAST, SIS NZ | 45.81 | 165.24 | 33 | 327 | 4.8 | |
| 11/07/1986 | 08:51:30 | W COAST, SIS NZ | 45.46 | 166.33 | 33 | 325 | 5.5 | 5.3 |
| 15/05/1988 | 18:45:53 | W COAST, SIS NZ | 43.85 | 168.68 | 10 | 4.9 | 5.5 | |
| 15/05/1988 | 19:42:00 | W COAST, SIS NZ | 43.94 | 168.46 | 4 | 4.0 | ||
| 18/01/1980 | No info found | |||||||
| 7/02/1980 | No info found | |||||||
| 5/08/1981 | 03:30:24 | No info found | ||||||
| 27/06/1982 | 16:48:17 | No info found | ||||||
| 30/10/1986 | 00:24:31 | No info found | ||||||
| 17/02/1987 | 09:52:30 | No info found |
Figure 3 replicates the data in Table 3, showing the diversity of T wave earthquake epicentre sources, but now showing a unique sonar travel path of earthquake energy converted into SoFaR sound waves travelling the Tasman and Coral Sea and converted back to seismic waveform recorded at the UQSS seismograph station, Brisbane (BRS). The blur of purple dots shows the prolific earthquake activity in the SW Pacific subduction zone region.
There appears to be a causal geometry between the western side of subduction fault zones and T wave generation.
The recently classified and submerged Zealandia continent (yellow/orange bathymetry) seems to effect the SoFaR depth or is it temperature/salinity effect. This is only a recent research discovery.
3.1. Student T wave travel times derived from epicentre location analysis - showing T wave velocities calculated
The right-hand columns in Table 3 show the T wave velocities calculated by the students in 1995 with only basic cartographic formulae to use. There is sufficient variation in this velocity observation to conjecture that:
- Accurate bathymetric path plots should better discriminate SoFaR travel time and seismic travel time.
- Is there a seasonality effect? There appear to be more T waves recorded from all cluster areas between May to September over the decadal data collection. Refer to Figure 4.
- Is it a salinity effect of the migrating Antarctic Converge boundary that could affect the ocean temperatures around Macquarie Island, Auckland Island and Balleny Island sourced T waves? (See Figure 5).
Figure 4.
10-year (1980-90) T wave occurrence at BRS seismographs, analysed by month of occurrence and regions of origin, to show any seasonality (Original plots by 1995 students).
Figure 4.
10-year (1980-90) T wave occurrence at BRS seismographs, analysed by month of occurrence and regions of origin, to show any seasonality (Original plots by 1995 students).
4. Discussion
4.1. Value of citizen science in the laboratory
The pilot study was an instructional organisational exercise for supervisory staff. It was successfully completed, giving the students a CSIRO curriculum certificate to take with their graduation. Mr Karunaratne later became a temporary seismogram record changer while he studied his PhD in biochemistry.
As a pilot scientific project, it brought together discussion and data collation techniques that were very new at a time of very few in-house computers. We were lucky to have begun data collection on a main frame computer within the university.
In all of this thematic discussion, we suspect there is a natural curiosity amongst people and listening to the earth’s noise, generated by earthquakes or related phenomena. The technology comes pre-packaged and is simple to deploy…just like a computer game.
4.2. Other discovered citizen science T wave recordings and research
Contemporary recent discussion with a prospective higher degree student reveals that a lot more Australian seismograph stations record these T phases on the East coast of Australia according to the ISC database [26] There is an interesting citizen science seismograph run by Mr A. Michael-Phillips (Coonabarabran, NSW) code name EPSO, which has documented T waves recorded on his seismographs from 2013 to 2019 [30]. This paper has also referred to the South Australian citizen science group that maintains, operates, and analyses T wave data. Impressively they repair their own instruments and raise money for them by selling hotdogs for a day [6].
4.3. Climate change related acoustic thermometry
As discussed in the review of recent T wave research literature, the T wave could give researchers an identifiable way of measuring the changes in temperature and salinity at depth in our oceans. Because their travel path (Figure 3) is a very selective inversion layer in the ocean between -1-5 km and -0.9 km depth (approx.) which could easily be disconnected if ocean temperature rises and salinity changes (see Figure 5). Of course, all types of animal life will be affected by such a catastrophe, especially krill which whales feed upon.
5. Conclusions
The authors have all been dedicated workers in the university sciences arena, and we enjoy communicating our work. We have grasped the urgency and dilemma of our epoch, the Anthropocene.
However, we believe that our paper demonstrates how the application of education for sustainable development (ESD), through the encouragement of citizen engagement in earth observation and other ongoing earth monitoring functions. It re-affirms the approach of UNESCO’s education sector response to the urgent and dramatic challenges the planet faces.
We also recognise the urgency of our situation. We are not talking about the implementation of an academic segue into science; we are talking about the mobilisation of a groundswell to gain both citizen comprehension and understanding of the climate change emergency and also about developing a stoic mindset of persistence, to bear some of the impacts about to befall the planet.
The strategy behind this paper’s approach was later signaled by Australia’s CSIRO, a premier scientific body. The prescient CSIRO report, Australia’s Biosecurity Future [31] looks at what this nation’s biosecurity aims should be over the next 10 years to 2030 and the steps needed to get there.
The challenges facing Australia’s biosecurity system are too big for any organisation or sector to tackle by themselves. The solution is a united, multifaceted approach. We need to harness the collective knowledge and eyes-on-the ground capability of our citizens, our communities, our industries, and our governments to ensure that all Australians are aware of their role in managing biosecurity risks and are working together to build the resilience of the biosecurity system. Shared responsibility involves improved community engagement; more systemic collaborations between Indigenous and non-Indigenous organisations and individuals; and working with industry to develop their role in surveillance. For it to work, every stakeholder has to understand its value and feel invested in Australia’s biosecurity. Together, system connectivity and shared responsibility will allow us to quickly share critical information, resources, and expertise. We’ll be able to coordinate prevention strategies, improve our rapid response, and efficiently identify research needs across the human health, agricultural, and environmental sectors. ‘Science’ is the application of scientific method to observations about the biophysical world.
We have already observed that the academic institutions in Australia are in a demoralised and cauterising economic mindset [32]. There will be no empathetic voluntary citizen science mobilisation coming from that quarter. The Australian public service is suffering a similar knowledge deficit after 10 years of neo-liberalising contracting out of their raison d’etre.
However, these big corporate focused university institutions do have sustainability programs endorsed by management. There may be an opportunity to implement a UNESCO defined ESD program addressed to university institutions’ senior management, pitching it as a benevolent service to the community and mankind rather than an academic studies initiative. However, it is imperative that the climate’s measurement is implemented.
We have observed that significant platforms exist already to mount a global UNESCO earth monitoring initiative, not for science’s sake, but for the education and preparedness of citizens who are unable to grasp what climate emergency impacts will befall them. Misinformation abounds. Anecdotally, we recently checked the Raspberry Shake website for a Shake seismograph located in Brisbane (Queensland) following the Magnitude 7 earthquake(s) in the Loyalty Islands and were able to verify that T waves are easily visible, with some visual tweaking.
We believe a parallel can be drawn in Australia, which leads the world in citizen initiated solar panel installation on their rooftops. A large percentage of the population have ignored the nay-saying energy corporations and have installed domestic solar rooftop power. Those same energy companies are now currently selling citizens interest free loans to install 9.5 Kw batteries that can feed power back into the grid at night, after being charged by the citizen’s solar panels during the day. Citizens are practical and capable problem-solvers.
Acknowledgments
Thanks to former UQSS Hon. Director, Dr Steve Hearn for his ongoing interest in teaching things seismological and geophysical. We most likely came under earthquake “enrapturement “through the inspired leadership and mentorship of the late “Happy Jack” Webb (Hon. Director UQSS). Thanks to fellow observors Mr Russ Cuthbertson, Mr Jack Millican, Mr Paul Gaffy and Mr Ted Laundon, who created the UQSS seismic data in the database and the pioneer UQSS Directors.
Conflicts of Interest
The authors declare no conflict of interest.
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Figure 1.
Figurematic arrangement of the P-, S-, and T-groups according to Increase in (S-P)-interval [9].
Figure 1.
Figurematic arrangement of the P-, S-, and T-groups according to Increase in (S-P)-interval [9].
Figure 2.
T wave recorded in BRS, 23-08-1949 from Queen Charlotte Is (Can). Earthquake.
Figure 3.
Map of locations included in Table 3 using modern computational techniques to plot the T Wave paths from epicenter to BRS Seismograph station. Index is Bathymetry depth in Metres (courtesy E. Sands).
Figure 3.
Map of locations included in Table 3 using modern computational techniques to plot the T Wave paths from epicenter to BRS Seismograph station. Index is Bathymetry depth in Metres (courtesy E. Sands).
Figure 5.
Major currents and fronts in the Southern Ocean and Subantarctic region: Antarctic Circumpolar Current (AAC), Antarctic Coastal Current (ACoC), Antarctic Divergence (AD), Antarctic Convergence (AC), Subtropical Convergence (STC) (4) (PDF) Obsidian floater washed up on a beach in the Chatham Islands: geochemical composition and comparison with other volcanic glasses [28].
Figure 5.
Major currents and fronts in the Southern Ocean and Subantarctic region: Antarctic Circumpolar Current (AAC), Antarctic Coastal Current (ACoC), Antarctic Divergence (AD), Antarctic Convergence (AC), Subtropical Convergence (STC) (4) (PDF) Obsidian floater washed up on a beach in the Chatham Islands: geochemical composition and comparison with other volcanic glasses [28].
Table 1.
T wave recorded in BRS, 23-08-1949 from Queen Charlotte Is. Earthquake.
 |
Table 3.
Student T wave travel times derived from epicentre location analysis.
| LOCATION | DATE/ | TIME OF ORIGIN | BRS TIME (UTC) | LAT (S) | LONG (E) | distance to BRS (degrees) | AZIMUTH | DEPTH | MB | MS | T travel time (secs) | Distance to origin (Km) | Velocity (Km/s) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3 | AUCKLAND ISLANDS | 06/08/81 | 11:25:47 | 11:52:20 | 49.76 | 163.96 | 23.93 | 335 | 33 | 4.6 | 1593 | 2655 | 1.730769 | |
| 4 | AUCKLAND ISLANDS | 03/05/87 | 12:26:53 | 12:52:33 | 49.17 | 164.6 | 23.57 | 333 | 13 | 4.6 | 1540 | 2620 | 1.473566 | |
| 5 | AUCKLAND ISLANDS | 02/23/91 | 14:59:40 | 15:26:00 | 49.1 | 164.9 | 23.63 | 332 | 10 | 4.9 | 1580 | 2620 | 1.08804 | |
| 6 | AUCKLAND ISLANDS | 02/25/81 | 11:03:02 | 11:30:10 | 49.35 | 164.58 | 23.02 | 333 | 19 | 4.6 | 1628 | 2620 | 1.609037 | |
| 7 | AUCKLAND ISLANDS | 04/22/86 | 21:53:05 | 22:19:23 | 40.06 | 163.6 | 24.04 | 336 | 10 | 4.8 | 1578 | 2665 | 1.73051 | |
| 8 | AUCKLAND ISLANDS | 05/25/81 | 10:44:25 | 11:09:40 | 49.27 | 164.41 | 23.71 | 334 | 12 | 1515 | 2635 | 1.730274 | ||
| 9 | AUCKLAND ISLANDS | 05/25/81 | 13:27:50 | 14:18:10 | 40.34 | 164.27 | 23.64 | 334 | 33 | 4.3 | 3020 | 2620 | 0.86755 | |
| 10 | AUCKLAND ISLANDS | 05/25/81 | 19:39:13 | 20:07:10 | 49.35 | 164.28 | 23.66 | 334 | 33 | 4.4 | 1677 | 2635 | 1.571258 | |
| 11 | AUCKLAND ISLANDS | 05/25/81 | 21:50:51 | 22:23:05 | 49.28 | 164.23 | 23.58 | 334 | 33 | 4.5 | 1934 | 2620 | 1.354705 | |
| 12 | AUCKLAND ISLANDS | 05/28/81 | 0:21:15 | 0:48:00 | 49.5 | 163.88 | 23.67 | 335 | 33 | 4.3 | 1605 | 2635 | 1.641745 | |
| 13 | AUCKLAND ISLANDS | 05/28/81 | 5:25:52 | 5:52:00 | 49.13 | 164.43 | 23.5 | 333 | 12 | 4.9 | 1568 | 2610 | 1.664541 | |
| 14 | AUCKLAND ISLANDS | 05/30/81 | 9:47:12 | 10:12:28 | 49.14 | 164.63 | 333 | 5.8 | 1516 | 2665 | 1.757916 | |||
| 15 | AUCKLAND ISLANDS | 05/31/81 | 7:57:07 | 8:24:00 | 49.82 | 164.1 | 335 | 33 | 4.2 | 1613 | 2665 | 1.709429 | ||
| 16 | AUCKLAND ISLANDS | 06/16/81 | 16:03:46 | 16:29:45 | 49.07 | 164.79 | 23.56 | 332 | 33 | 5.3 | 1559 | 2620 | 1.64469 | |
| 17 | AUCKLAND ISLANDS | 08/16/81 | 5:10:11 | 5:41:45 | 49.54 | 104.32 | 23.84 | 334 | 33 | 4.5 | 1894 | 2645 | 1.005017 | |
| 18 | AUCKLAND ISLANDS | 10/26/89 | 2:14:14 | 3:09:00 | 50.67 | 162.76 | 24.47 | 10 | 4.4 | 3286 | 2755 | 1.786641 | ||
| 19 | AUCKLAND ISLANDS | 11/21/89 | 14:37:39 | 15:03:21 | 50.18 | 164.6 | 23.97 | 10 | 5.6 | 1542 | 2665 | 1.696372 | ||
| 20 | AUCKLAND ISLANDS | 12/20/88 | 13:53:32 | 14:20:10 | 50.5 | 163.1 | 21.57 | 10 | 4.8 | 1598 | 2400 | 0.730371 | ||
| 21 | BALLENY ISLAND | 07/09/89 | 5:48:02 | 6:28:10 | 61.4 | 154.1 | 34.01 | 10 | 5.4 | 2408 | 3780 | 3.624161 | ||
| 22 | LOYALTY ISLANDS | 06/07/81 | 3:08:34 | 3:25:36 | 22.29 | 171.04 | 17.86 | 250 | 114 | 6.3 | 1022 | 1980 | 1.962339 | |
| 23 | LOYALTY ISLANDS | 06/09/81 | 11:02:41 | 11:19:30 | 21.5 | 160.61 | 16.41 | 246 | 30 | 6 | 1009 | 1820 | 1.786065 | |
| 24 | LOYALTY ISLANDS | 01/05/86 | 19:31:42 | 19:49:00 | 21.85 | 170.13 | 16.72 | 247 | 71 | 5.7 | 1038 | 1855 | 1.873737 | |
| 25 | LOYALTY ISLANDS | 01/15/86 | 20:17:31 | 20:33:57 | 21.37 | 170.31 | 17.06 | 246 | 144 | 6 | 986 | 1900 | 1.830443 | |
| 26 | LOYALTY ISLANDS | 01/I6/80 | 4:00:27 | 4:17:50 | 21.85 | 170.58 | 17.1 | 56 | 5.4 | 1043 | 1900 | 1.8591 | ||
| 27 | LOYALTY ISLANDS | 02/17/91 | 6:59:14 | 7:16:23 | 21.17 | 169.76 | 16.67 | 245 | 73 | 5.5 | 1029 | 1865 | 0.79126 | |
| 28 | LOYALTY ISLANDS | 07/31/88 | 12:50:11 | 13:06:41 | 22.26 | 171.02 | 16.61 | 85 | 5.7 | 990 | 1845 | 1.904025 | ||
| 29 | LOYALTY ISLANDS | 09/21/88 | 11:04:51 | 11:21:00 | 22.27 | 170.97 | 17.28 | 88 | 5.1 | 969 | 1920 | 1.865889 | ||
| 30 | LOYALTY ISLANDS | 10/29/81 | 12:06:48 | 12:23:47 | 23.65 | 169.11 | 15.21 | 252 | 18 | 5.1 | 1019 | 1690 | 1.85524 | |
| 31 | LOYALTY ISLANDS | 11/15/84 | 2:46:21 | 3:03:22 | 22 | 170.01 | 17.33 | 248 | 110 | 6.3 | 1021 | 1920 | 1.047262 | |
| 32 | MACQUARIE ISLAND | 03/09/87 | 6:40:11 | 7:17:00 | 58.86 | 158.8 | 31.7 | 15 | 5.9 | 2209 | 3520 | 2.046512 | ||
| 33 | MACQUARIE ISLAND | 05/23/84 | 5:16:34 | 5:44:00 | 51.88 | 161.08 | 25.25 | 342 | 10 | 5.8 | 1646 | 2800 | 2.777778 | |
| 34 | MACQUARIE ISLAND | 09/17/90 | 13:47:26 | 14:15:00 | 53.17 | 159.64 | 26.25 | 346 | 10 | 5.9 | 1654 | 2910 | 1.767922 | |
| 35 | MACQUARIE ISLAND | 11/15/80 | 19:10:57 | 19:48:37 | 52.34 | 160.07 | 22.61 | 10 | 5.7 | 2260 | 2500 | 1.511487 | ||
| 36 | MACQUARIE ISLAND | 12/31/84 | 21:42:10 | 22:21:27 | 60.21 | 153.8 | 32.81 | 359 | 10 | 5.3 | 2357 | 3645 | 1.650068 | |
| 37 | NEW CALEDONIA | 02/24/91 | 9:36:57 | 9:52:00 | 22.72 | 166.64 | 13.4 | 247 | 33 | 4.9 | 903 | 1490 | 1.02759 | |
| 38 | NEW CALEDONIA | 09/18/81 | 9:07:17 | 9:24:05 | 22.81 | 167.6 | 14.22 | 248 | 33 | 4.4 | 1008 | 1580 | 1.644121 | |
| 39 | NEW CALEDONIA | 12/17/88 | 0:58:14 | 1:13:45 | 20.93 | 167.53 | 13.15 | 25 | 5.5 | 931 | 1465 | 1.011661 | ||
| 40 | NEW ZEALAND | 01/28/80 | 12:30:56 | 12:55:10 | 45.26 | 167.5 | 21.36 | 118 | 5.1 | 1454 | 2375 | 3.149867 | ||
| 41 | NW OF NZ | 05/25/88 | 13:25:23 | 13:41:39 | 30.7 | 167.7 | 13.43 | 10 | 4.8 | 976 | 1490 | 1.219313 | ||
| 42 | NW OF NZ | 07/26/87 | 21:59:38 | 22:12:12 | 30.23 | 105.8 | 11.77 | 10 | 5.2 | 754 | 1310 | 1.342213 | ||
| 43 | SOLOMON ISLANDS | 09/27/85 | 3:39:08 | 3:59:30 | 9.81 | 165.85 | 18.31 | 200 | 33 | 6.2 | 1222 | 2035 | 1.465083 | |
| 44 | SOUTH ISLAND NZ | 08/30/80 | 5:55:53 | 6:19:02 | 45.06 | 167.67 | 21.27 | 321 | 112 | 4.6 | 1389 | 2365 | 1.53372 | |
| 45 | SOUTH ISLAND NZ | 04/07/82 | 15:42:24 | 16:05:00 | 21.15 | 320 | 10 | 4.7 | 1356 | 2355 | 1.736726 | |||
| 46 | SOUTH ISLAND NZ | 12/09/85 | 12:53:02 | 13:16:30 | 45.4 | 107.36 | 21.4 | 322 | 80 | 5.1 | 1408 | 2380 | 1.690341 | |
| 47 | SOUTH ISLAND NZ | 03/06/88 | 23:27:35 | 23:47:20 | 44.06 | 107.04 | 21.11 | 82 | 5.7 | 1185 | 2455 | 2.07173 | ||
| 48 | SOUTH ISLAND NZ | 02/15/91 | 10:48:09 | 11:12:16 | 42.08 | 171.59 | 21.23 | 308 | 8 | 5.8 | 1447 | 2355 | 1.627505 | |
| 49 | SOUTH ISLAND NZ | 05/16/88 | 9:55:34 | 10:19:00 | 44.17 | 168.13 | 12 | 4.2 | 1406 | 2345 | 1.667852 | |||
| 50 | SOUTH ISLAND NZ | 05/27/81 | 18:57:18 | 19:23:00 | 48.48 | 164.48 | 332 | 12 | 4.6 | 1542 | 2345 | 1.520752 | ||
| 51 | SOUTH ISLAND NZ | 07/11/BG | 16:56:38 | 17:20:05 | 44.54 | 167.45 | 20.78 | 321 | 12 | 4.2 | 1407 | 2310 | 1.641791 | |
| 52 | SOUTH ISLAND NZ | 09/27/84 | 21:41:05 | 22:04:21 | 44 14 | 168.66 | 21.04 | 317 | 1 | 4.7 | 1396 | 2345 | 1.679799 | |
| 53 | SOUTH ISLAND NZ | 11/22/81 | 18:37:00 | 19:00:15 | 44.46 | 167.63 | 20.8 | 320 | 18 | 1395 | 2310 | 1.655914 | ||
| 54 | SOUTH ISLAND NZ | O6/09/88 | 12:10:04 | 12:33:30 | 44 | 167.48 | 65 | 4.2 | 1406 | 2345 | 1.205036 | |||
| 55 | SOUTH ISLAND NZ | O6/14/88 | 15:43:21 | 16:07:00 | 44.4? | 168.34 | 8 | 4.2 | 1419 | 2345 | 1.652572 | |||
| 56 | VANUATU | 10/07/86 | 12:41:29 | 12:58:08 | 19.52 | 169.16 | 16.94 | 239 | 21 | 6.2 | 999 | 1880 | 1.881882 | |
| 57 | VANUATU | 12/08/90 | 21:25:24 | 21:41:50 | 19.48 | 169.12 | 16.93 | 239 | 164 | 6.3 | 986 | 1880 | 1.906694 | |
| 58 | VANUATU | 04/00/84 | 23:08:22 | 23:25:10 | 18.95 | 108.89 | 17.02 | 237 | 185 | 5.8 | 1008 | 1890 | 1.875 | |
| 59 | VANUATU | 05/28/81 | 21:04:22 | 21:18:00 | 15.01 | 166.97 | 18.06 | 225 | 121 | 4.8 | 818 | 2010 | 2.409287 | |
| 60 | W COAST, SOUTH ISLAND NZ | 03/04/86 | 14:09:04 | 14:33:22 | 45.81 | 165.24 | 20.89 | 327 | 33 | 4.8 | 1458 | 2320 | 1.591221 | |
| 61 | W COAST, SOUTH ISLAND NZ | 11/07/86 | 8:27:46 | 8:51:30 | 45.96 | 166.33 | 21.43 | 325 | 33 | 5.3 | 1424 | 2380 | 1.671348 | |
| 62 | W COAST, SOUTH ISLAND NZ | 01/31/85 | 4:32:58 | 4:56:00 | 46.01 | 165.16 | 21.02 | 328 | 10 | 5.8 | 1382 | 2335 | 1.68958 | |
| 63 | W COAST, SOUTH ISLAND NZ | 05/15/88 | 18:26:16 | 18:45:53 | 43.85 | 168.68 | 20.84 | 10 | 5.5 | 1177 | 2310 | 1.962617 | ||
| 64 | W COAST, SOUTH ISLAND NZ | 05/15/88 | 19:18:25 | 19:42:00 | 43.94 | 168.46 | 20.8 | 4 | 4 | 1415 | 2310 | 1.632509 | ||
| 65 | W COAST, SOUTH ISLAND NZ | 06/15/81 | 2:31:18 | 2:56:00 | 48.46 | 165.11 | 23.12 | 331 | 33 | 5.2 | 1482 | 2565 | 1.730769 | |
| 66 | W COAST, SOUTH ISLAND NZ | 06/27/81 | 21:39:00 | 22:04:00 | 48.8 | 164.2 | 23.14 | 333 | 33 | 4.4 | 1500 | 266 | 1.71 | |
| 67 | W COAST, SOUTH ISLAND NZ | 09/21/85 | 13:50:15 | 14:14:26 | 46.37 | 165.78 | 21.86 | 327 | 22 | 4.9 | 1451 | 2435 | 1.678153 | |
| 68 | W COAST, SOUTH ISLAND NZ | 12/23/81 | 14:58:19 | 15:24:00 | 47.74 | 105.77 | 329 | 10 | 3.8 | 1541 | 2665 | 1.752137 |
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