Newsletter of the

Seismological Association

of Australia Inc.

Nov­Dec 2017

The volcanic nature of the island of Bali is evident in thisshaded relief image generated with data from the Shuttle Radar Topography Mission (SRTM), image courtesy of NASA Earth Observatory.

Seismological Associationof Australia Inc.

Newsletter of theSeismological Association of Australia Inc.

PO Box 682, Mylor SA 5153

Your Committee

Chairperson ­ Blair Ladem: 0407 189 061 e: blairl@bettanet.net.au

Chief Seismologist ­ David Lovep: 08 8336 8003 e: david@earthquake.net.au

Public Officer ­ Paul Hutchinsonm: 0419 829 216 e: windfarmer@bigpond.com

Treasurer ­ Joe Gridam: 0407 558 036 e: joe.grida@internode.on.net

Editor ­ Peter Graym: 0418 829 632 e: weaksignals@iinet.net.au

The SAA can be contacted by post to theaddress above, or by email to any member of

Committee, as listed above

Membership of the SAA is open to all, with theonly prerequisite being an interest in seismology.Membership applies for the calendar year(January through to December)

Membership fees are:Full member $50

A Membership application form can be obtainedfrom the Treasurer.

Member SubmissionsSubmissions for inclusion in the Newsletter arewelcome from all members; submissions may beheld over for later editions.Wherever possible, text submissions should besent via email in almost any word processingformat. Your name may be withheld only ifrequested at the time of submitting. Imagesshould be high resolution and uncompressed,although high resolution JPEGs are acceptable.

All enquiries and submissions should beaddressed to the Editor and preferably sent byemail to weaksignals@iinet.net.au

A word from the ChairpersonWelcome to our third newsletter. It’s been aninteresting and busy first six months to say theleast. We’ve had our first AGM, with membershaving the upmost confidence in the interimOffice bearers who were re­elected unopposed.I wish to thank everyone for their continuedsupport to our Association.We welcome Peter Gray to the role of Editor andthank Joe Grida for the superb effort on the firsttwo newsletters for our Association. You’ve seta high standard Joe!We are still looking for a member to take on therole of Secretary. Should some wish to take thaton, we would be most thankful.Our seismic network is healthy, but there is stillmuch work to be done in servicing sites andsome repairs / upgrades. I’d also like to thankthe ongoing support by the farmers andmembers who host instruments. Without you all,we would not have a network.It is with sadness that I have to advise you all ofthe passing of John Harris (MPTV) and ourcondolences to his wife Joan. Joan will continueto host the instruments that John built and ourserver at Morphett Vale, thank you Joan.Best wishes to everyone for the festiveseason, Blair

Newsletter of the SAA Inc. Nov­Dec 2017Page 2

FarewellJohn Harris

When the Mount Barker earthquake rattledAdelaide in April 2010, John rang the GeologicalSurvey of SA with his felt report, also telling usthat he had a digital record of it from aninstrument he had built. We connected him withVic Dent, and John became the first PSN user inSA, located at Morphett Vale (MPTV).On 27 June 2011 he was at the first Adelaideseismology meeting at Payneham, where wetalked late into the night. He went north with Victhe following day, to install PSN instruments atPeterborough and Jamestown schools. Thiswent well, and turned out to be really usefulwhen a swarm of earthquakes happened rightbetween them at Yongala in September.John organised the second Adelaideseismologists meeting, which was held at theO’Halloran Hill Pistol Club in early 2012.Vic connected John with Dale Hardy, and theycollaborated on quite a few innovative projects.John installed at his place one of the first“Forced Balance” long period recorders that Dalehad designed. Like Dale, John seemed to havean ever­lasting supply of enthusiasm for scienceand technology, and was always keen to applyhis knowledge to new, little, but very usefuldevices. The MPTV site has been one of thelongest running stations to the ACG website,with at last count, eight channels running.

John built a small calibrator that worked byputting a step current into a signal coil. Thisenabled better calibration than the methodpreviously used by the SA network.John and Joan bored (by hand) and cased a10m hole on their property. John had parts of adownhole probe and was planning to install it tosee if the noise level could be reduced. InJanuary this year, at the same time as we weredeciding to form an association, John receivedthe bad news that he had mesothelioma. InMarch, John and Joan helped in thedecommissioning of the Myponga site, butalready John was needing to take things easy,

so Joan did the heavy lifting. Despite hisdeteriorating health, John put in a big effort andcame to an evening meal on 3rd August, whenAdam Pascale was visiting to install a newGecko and Prism. It was his last outing with us.John died at home on November 10th. Hedonated his body to science, and it was quicklytaken away. Joan will organise a smallrememberance service next year. When thebody remains are eventually released, Joan willtake his ashes to Norfolk Island, a favouriteplace for both of them.

We will miss you John.

Newsletter of the SAA Inc. Nov­Dec 2017Page 3

Left to right Nina & Blair, Paul, Adam, Heather, John & Joan

SAA News& rumblings

Annual General Meeting of the SAAThe inaugural AGM of the association was heldon October 30th at the offices of Nova Systems,Mile End SA. Of the 27 paid up members of theassociation, 15 were in attandance and 3submitted apologies. The interim committeepositions were declared vacant and personsnominated for the new committee were electedunopposed. The list of committee members andtheir contact details can be found on Page 2 ofthis and future Newsletters. Unfortunately, theposition of Secretary remains unfilled. Shouldanyone have a change of heart, there aremechanisims in the constitution to allow this.David Love gave a presentation on New Zealand

SAA DatabasesDid you know that the SAA maintains severaldatabases? These are to help manage theassets of the association and assist members tosupport their seismic sites.

Station Register: While many of the ex.Geological Survey of South Australia (GSSA)sites are similar in equipment configuration,there are significant differences between sites.As for the privately owned/operated sites, theequipment mix can be made up from whateverwas available or convenient to use. In anattempt to maintain a robust and reliable seismicnetwork, the more we know about the wayeveryone's seismic station works, the better wecan provide technical support, should the needarise. This is particularly prudent when remotesites are considered. It may take several hourstravel to visit a site that requires somemaintenance and it's a long trip back to pick up aconnector specific to a Guralp CMG­6T, if wethink there's a Kinemetrics SS­1 fitted at the site.

Asset Register: The association has aconsiderable investment in physical assets thatneed to be tracked, accounted for and possiblyeven insured. The Asset register encompassesall equipment in service at seismic stations andin offline storage. With this information, theseismic network can be improved, as required,from existing equipment or help identifyweaknesses that require replacement with newequipment.

Newsletter of the SAA Inc. Nov­Dec 2017Page 4

earthquakes and a short summary of the seismicsites currently being operated by the SAA. Themeeting concluded with supper and a groupphoto (below)

It's your NewsletterWelcome to your Newsletter. I am just the neweditor and I hope you like this format. As wedon't produce and post out hard copies, I thoughtthat the A4 landscape layout might be better foronscreen reading. I stress again that this isyour Newsletter and it will only be as good asthe content that members contribute to it. If youwant better resolution images, let me know andI'll increase the size. Once the SAA website isup and running, you will be able to downloadyour Newsletter directly yourself. While we arerestricted to distribution by e­mail, I'm trying tokeep the file size within reasonable limits, manyISPs still restrict email attachment sizes.

Left to RightJudy Carter

Nina StansfieldLyn Grida

Alison WallaceBlair Lade

Ian AndersonPaul Hutchinson

David MillarJim DeerJoe Grida

David LoveHeather LoveJohn Duffield

SAA News& rumblings

November in Canberra

The annual Australian Earthquake EngineeringSociety Conference is normally held in lateNovember. This year it was held in Canberra, atGeoscience Australia (GA). SeismOz, theAustralian Seismologists Meeting was held onthe morning before the conference, and invitedpeople attended a workshop on the AustralianHazard map being developed by GA. This allmade for a very busy Thursday to Sunday.

Big talking points through all these meetingswere the hazard map and moment magnitude.GA had presented a hazard map to the buildingcode committee, with much lower hazard levelsthan the previous version. For this and otherreasons, the map was not accepted and theprevious one will be used in the next buildingcode update. The hazard map work has beendone using moment magnitude, however no­onein Australia is currently calculating momentmagnitude for Australian earthquakes. To makea moment magnitude catalogue, othermagnitudes were converted, which caused muchdiscussion. For moment magnitude to become anormal part of Australian seismology, we need tohave more well calibrated stations, studiesacross the country to determine the absorption

at a range of frequencies, and simpler software,and training. Moment magnitude is a morecomplicated beast than Richter.

SeismOz has become a regular meeting,particularly for observational seimologists aroundthe country to say what they have done in thepast year, and intend to do in the next. It is fairlyinformal with questions and discussion, but onlylimited academic material. There werepresentations from Geoscience Australia,Australian National University (ANU),Seismology Research Centre (SRC), Universityof Melbourne, and I presented a bit covering theend of GSSA, the start of SAA, and PSN. There

Newsletter of the SAA Inc. Nov­Dec 2017Page 5

Do you have some interesting news that youwould like to share with other members orsomething seismic you want to sell ? If so,please submit it to weaksignals@iinet.net.aufor inclusion in the next edition.

is much happening around Australia when it is allpresented at once! ANU reported that their newin­house recorder ‘Terrasaur” runs on 200mW.They are intending to set up about 80insturments in a line between Oodnadatta andMarla in 2018. GA reported that the AustralianSeismological Report 2016 has been delayeddue to the extra seismic activity in the year, andtheir desire to improve the report.

SeismOz attendees take a break for the camera

SeismOz 2017

TennantCreek Pt. 2

We had almost 10 inches!In the morning we pulled all of Geopeko’s 4WDsout of very boggy carparks and did little else, itwas still raining a bit. I drove down the StuartHighway a few days later just to see how itlooked. Water everywhere! The ground was sowet that the snakes had come onto the highwayto dry out. There were a few cars bogged on theside of the road (silly people) and I helped pull afew back onto the road with my 4WD.Reaching the Station turnoff, it was obvious thatdriving any appreciable distance down the dirtroad was going to be risky and the chance ofgetting there and back without either sliding offthe hard surface or breaking through the top waslow.I decided to go back to Tennant Creek and getone of my motor bikes, that way I could walk andride when the conditions were appropriate. Backto the Station turnoff, it was wet, it was muddybut I got to the station after about an hour's hardride down the 10 miles of dirt. It looked verygrim and the ride had tired me out a lot. I wasn’tgoing to be able to do that every day and I calledup Geopeko’s manager Paul le Messurier on the2way and told him that I was going to shuteverything down as further trips would onlydamage the road more and the risk of personalinjury would grow with each trip.

He was ‘sort of’ happy with that, so I turnedeverything off, made a cup of tea then shut downthe generator. Warramunga was ‘off the air’ andI started the ride back to town arriving exhaustedfrom the day’s work.The Geopeko staff helped retrieve cars andtrucks bogged all over town. It was sort of ‘fun’and hard work but it was different from what wehad all been doing. For the next 2 weeks we didodd jobs and serviced Toyotas while the weatherimproved somewhat and the ground dried out abit. I drove to the station turn off accompaniedby 2 other vehicles with as much chain, Wallaby

jacks, timber, shovels etc that we could muster,Strewth, there was a remote chance that wemight get bogged.Now getting bogged in the Northern Territoryduring the wet season is expected and nothingto be overly concerned about. After all, legendhas it that the township of Tennant Creek iswhere it is today because the beer truck gotbogged there many years ago and it was so badthat they decided it was less work to move thetown which was then located 7 miles to the northof the beer truck, than get the beer truck to thetown.

Newsletter of the SAA Inc. Nov­Dec 2017Page 6

It’s probably only a one carton bog

TennantCreek Pt. 2

Bogs are rated according to how well you gotbogged and how much it takes to get‘unbogged’. Note how much, not how long ittakes to get unbogged.A one carton bog is hardly worth writing about,expecially if there are a few people who are thebogees. Where as a ten carton bog is prettydamm good no matter who is there...The image (previous page) was taken inTennant Creek last year by persons unknown,and shows the typical country and conditions Iexperienced each wet while at Warramunga, it’sprobably only a 1 carton bog. Google ‘gettingbogged in the Northern Territory’ for somefurther imagery.There are stories of 20+ carton bogs… some ofthe trucks might even do more!Well, we probably had a six carton one, a bithard to tell as we had three 4WDs bogged andno cartons! Out came the shovels, each mantrying to prove that he was better than the nextat getting ‘unbogged’. It was a stinker of a dayand time flies when you're having fun, so as thesun slowly crept towards the western horizon itwas finally time to fess up, get on the radio andcall for help. About half an hour later, the bigballooned tyred, 6WD RFW ‘unboggable’ truckand a couple of other Toyotas turned up.Despite the advertising, we managed to get the

RFW bogged to the axles but eventually we allgot pulled out by the 4WDs and returned toTennant Creek for dinner, skip dinner, it was a 6carton bog and 6 cartons it was going to be.Didn’t earn a lot that pay week!!A couple of days later (well it was a 6 cartonbog), we attempted again to get to the Stationwith considerably more luck. A couple of thecreek crossings near the station on the road inhad been washed away by all the rain and wouldneed considerable repair work later on, but withdifficulty, we made it to the Station.Arriving at the station, first job was to put thekettle on, start the Lister HR3 diesel generatorand have a quick look around the lab foranything that might need immediate attention.We had 2 of these generating sets, with 25kVADunlite alternators in the station power shed.

Newsletter of the SAA Inc. Nov­Dec 2017Page 7

Now, we all drank black tea in Tennant Creek(well that was during the day time, night timewas beer as if you couldn’t guess) because there

were no fresh milk deliveries to the town. All youcould buy was tins of powdered milk, and forthose that don’t know, the powdered milk in thecoffee sort of curdles and isn’t the nicest to drink.So back then, tea it was.I started to turn the station back on. First on thelist was the ‘clock’ which came alive; so did theold Eddystone shortwave radio. Now all I had todo was find the now defunct Australian timesignal from VNG between the crackle fromdistant lightning storms for a time check.https://en.wikipedia.org/wiki/Radio_VNGThe seismic signals from the array came into thestation two ways; most via two antennae and abunch of 450MHz receivers on top of the nearesthill, but a couple of the closest instruments camein via overhead ‘telephone’ wires on woodencreosoted poles. I turned on the receiver powersupplies and about half of the array came to life.The local short period pit (Blue 2 I think) that fedthe helicorder rack was alive and the LP wasmaking noises but didn’t sound very well. Robbofrom England had said that it was very easy tomake the LP unhappy; well it had been off for 2weeks, so I’ll leave it alone for a few days towarm up. I found the VNG radio signal, setupthe oscilloscope and set the clock. Warramungawas ‘back on the air’.A new waxed paper sheet on the helicorder (Idid have ink charts but not for seismic) andturned on the inverter, which was synced to50Hz from the clock, and I had a trace on theheli... So far so good. New tapes on the 24 trackEMI logging tape decks, pushed the start button

TennantCreek Pt. 2

and away we went; data again.I sent a radio signal from the lab to test theremaining receivers; two had died but the restappeared to be OK, so it was probablytransmitter failures that had killed the rest.I then looked at the microbarograph arraysignals that come into the lab via overhead‘telephone’ wires, nothing, not even a hint. Bit ofa bugga that, probably the wires had been hit bylightning and it was going to be a far amount ofwork to recover.Having put the seismic part of the station backon air, we decided to call it a day, locked up andstarted the drive home.One of the 4WDs slid off the road, and wentstraight down to the axles. We managed to pullit back onto the road, but got covered in mud,the side of the road was so soft, you could pusha 6 foot star picket down a couple of feet withouttrying.Bush work was going to have to wait!Back in town, I sent a telex from the Geopekooffice to the ANU and UK advising of the currentstatus. Time for the pub… it had been a longday.

This "Tales of Tennent Creek Part 2" , article was submittedcourtesy of Blair Lade. It was written at short notice whenthe original lead article was delayed by technical issues.

Newsletter of the SAA Inc. Nov­Dec 2017Page 8

Data, data, where to send my dataFor seismic sites using the Kelenji Echo typerecorders and other devices producing miniseedfiles, you will probably be familiar with sendingyour data to the Melbourne Uni Eqserver at:

http://meiproc.earthsci.unimelb.edu.au/eqserver/

The SAA was able to salvage a functional serverfrom the closure of the GSSA, it is available at:

http://ade­eqserver.dyndns.org:8080/eqserver/

please contact David Love if you would like toadd your station.

If you are running the Webtronics WinSDRsoftware, you can also be set up to send data tothe SAA Eqserver. However, WinSDR is onlyable to send event data in miniseed format.When a triggered event is recorded by WinSDR,only then will a trace appear on the SAAEqserver.Of course you have the option of the RegionalSeismic Network site at the Australian Centre forGeomechanics at:

http://www.regional­seismic.net/

Just a bit more SAA News(to fill the page)

and the Regional Seismic Users website at:

http://www.rsuw.daleh.id.au/index.html

For those of you who do use the ACG­RSNwebsite, I'm hoping to do an article in a futureNewletter on some of the advanced featuresavailable to users with log­in priveleges.

Bunnings BBQ FundraiserThere is a significant cost to maintaining anetwork of seismic stations. There are dataplans for communications, replacement batteriesfor back­up power requirements and thoseunexpected failures that happen from time totime. As an association with a small butenthusiastic membership, we don't want to useall our limited resources on these tasks. ABunnings BBQ has been booked for early 2018at the Mt. Barker (SA) store, on a date to bedetermined and announced soon. Volunteerswill be needed for the day, hopefully the morethe merrier. We hope to have some demohardware onsite to keep the punters amusedwhile we scrape the plate for something edible.You have been warned, any doctors certificatespresented on the day will be used to light theburners!

Events fromthe past

A NORTHERN MYSTERY!SIX WEEKS OF EARTH TREMORS.Mr. John Melrose, of Ulooloo, writes to TheRegister:—"Daily, for the last six weeks or more,residents round about this district have beenwatching the press for some explanation of whathas gone wrong with the works of the earth, orsomething having influence over it. So far as Ihave noticed, only one correspondent has re­marked on the phenomena, and that one was, Ithink, from Spalding. In the last six weeks wehave hardly missed a day without feeling earthwaves or hearing rumblings. On some daysthere have been as many as a dozen; and theyappear to me to be generally from the north­west, al­though many people think they comefrom other directions. The duration is usuallyshort. Mostly they are simply rumbling sounds asof a heavily laden trolly, with which the horseshave got away over how­low ground or over alarge bridge. Others shake buildings and rattlethe gas globes and loosely hanging articles. Thetremors or noises average three or more in aday; so that I am well within the mark inestimating the total number heard or felt atsomething over a hundred. We would be glad tohear what our Government Meteorologist has tosay on the subject, and whether theseismograph has recorded anything".

Governor Astronomer's Statement.The Government Astronomer (Mr. G. F. Dodwell,B.A.), when shown the above letter, stated thathe had received a some­what similar,communication from the post­mistress at Hallett,who stated that a great number of tremors, not ofa severe character, had been felt there,accompanied by a noise like the rumble of aladen dray. At times they appeared to shake thehouse as the passing of a heavy vehicle would.The tremors were most severe on theBooborowie Plain, 10 miles distant, between thetwo ranges. Mr. Dodwell, continuing, said: "Ihave examined the seismograph record for theperiod November 25 to 28, and find that the first­mentioned day was fairly quiet, but that on theother days — particularly November 27 and 28— micro­seismic tremors are indicated, more orless continuously, and mainly during the hoursbetween 3 p.m. and 8 a.m. Similar experienceswere recorded a few years ago, but not over solong a period as your correspondent indicates.The dry season may have some causativeinfluence in these phenomena. At the time ofthe last drought, 1914, considerable tremors,which were perhaps the result of a progressiveshrinkage of the ground through the drying to aconsiderable depth of the moisture in the earth'ssurface strata, caused cracks to develop inbuildings. Many of the deeper­seated springsalso failed at that time. In places where thereare geological 'faulting' and instability, such asoccur in certain parts of our ranges, andparticularly the Flinders Range, the effect of a

dry season may thus be the factor in causingminor readjustments and consequent tremors."Considerable public interest has been aroused inconsequence of reports which have appearedrecently in The Register regarding continuedearth tremors in the north. Some time ago ourSpalding correspondent drew attention to themystery and a further communication on thesubject from Mr. John Melrose, of Ulooloo, waspublished on Wednesday, together withcomments by the Government Astronomer (Mr.G F. Dodwell, B.A.). The latest report fromSpalding states: "During the past fortnight wehave experienced three and four earthquakesdaily. Some of the tremors have been only slight,but others have been much more pronounced".On Sunday night, at about 9 o'clock, theseverest of the lot occurred. Travelling in aneasterly direction, the rumble could be heard forfully 10 minutes. The ground shook, and thenoise was like that of a big flood as it proceededthrough the hills to the east of the town. Walls ofbuildings were cracked and pictures and plasterfell to the ground.This "swarm of earthquakes" article was submitted courtesyof Kevin McCue and originally published in The RegisterNewspaper back in 1919.

Newsletter of the SAA Inc. Nov­Dec 2017Page 9

Have you seen an interesting article that youwould like to share with other members? Ifso and you are able to provide some detailsof it's source (for copyright reasons), pleasesubmit it to weaksignals@iinet.net.au forinclusion in a future edition.

MemberSites

MTON: Middleton, South AustraliaLocation: 35.483438S, 138.678381WOwner/Operator: Peter & Maxine Gray

As if we really needed another seismometer onthe Fleurieu Peninsular. The Geological Surveyof SA had seismometers at Myponga (MYP) andon the fringes at Strathalbyn (STR2), Kelly HillCaves, Kangaroo Island (KELC). PaulHutchinson was running Hindmarsh Valley(HMV1) and in the process of developing ThePeters Seismic Observatory (TPSO). JohnHarris's private station at Morphett Vale (MPTV)rounded off coverage of the area quite nicely.Still, David Love was not about to say no toanother cog in the wheel.Armed with a Willmore Mk.II courtesy of BlairLade, a 16bit ADC/filter card from Larry atWebtronics and an old PC running WinSDR onWindows XP, I set about constructing my veryown seismic station. Housing the seismometerwas to be my biggest problem, having been toldwhat happens to seismic stuff when it get wet.Fortunately, they grow FRP pipe offcuts in apaddock near McClarenVale so I bought oneand set about using it as a vault. I was unable tofind bedrock on the site so a concrete base wasformed and the seismometer/electronicspackage installed into my makeshift vault.

An old satellite dish was used as a lid for thevault. The PC was installed in the garage some30m from the vault and hardwired back to thehouse for data and power. Data links to theinternet were established using a 3G wirelessmodem. MTON went live on the ACG website inApril 2014 and then added to RSUW in May. Ithas made a reliable and consistent contributionto the seismic record since then.

Several upgrades have been undertaken in theinterim period, the Windows PC (120W) wasreplaced with a Linux Notebook (14W) runningWinSDR. A Sprengnether HSA­3 accelerometercourtesy of David Love was added to providethree axis to complement the vertical Willmore.The 3G modem was replaced when the NBNSkymuster Satellite service was introduced in2016. Most recently, the Linux Notebook wasreplaced by a Raspberry Pi 3B Single BoardComputer (2.6W) running WinSDR.

Newsletter of the SAA Inc. Nov­Dec 2017Page 10

1.4m dia FRP pipe prior to concrete pour

Willmore Mk II in its styrofoam filled case

The primary purpose of each upgrade was toreduce power consumption and 24/7 runningcosts. With the exception of the NBN service,each upgrade was able to achieve significantsavings over the previous configuration withoutsacrificing system stability or reliability. Futureupgrades will focus on improvements to dynamicrange by replacing the 16bit ADC with theWebtronics 24bit ADC and reducing the effectsof wind and rain noise on the roof of the vault.

It's just me and the spiders