Tasmanian Geological Survey Record 2009/04 Historical accounts of tsunamis in Tasmania by M. K. Morris & C. Mazengarb Department of Infrastructure, Energy and Resources Mineral Resources Tasmania 144° 145° 146° 147° 148°148° 40° LOCATION MAP 40° CURRIE GRASSY NORTH 0 50 100 km y a B k c u D Circular Head Bridport Wynyard 41° 41° Burnie Ulverstone DEVONPORT St Helens LAUNCESTON 42° 42° QUEENSTOWN Swansea Triabunna Risdon New Town Bay Hobart 43° 43° Port Arthur Franklin Derwent Crowthers Bay River Fortescue Bay Huon River Oyster Mt Brown Cove Port Davey Department of Infrastructure, Energy and Resources Mineral Resources Tasmania Cockle Creek 145° 146° 147° 148° Figure 1. Locations discussed in text Mineral Resources Tasmania PO Box 56 Rosny Park Tasmania 7018 Phone: (03) 6233 8377 l Fax: (03) 6233 8338 Email: [email protected] l Internet: www.mrt.tas.gov.au CONTENTS Abstract ……………………………………………………………………………… 4 Introduction …………………………………………………………………………… 4 Historical accounts ……………………………………………………………………… 5 30 September 2007 ……………………………………………………………………… 5 3 May 2006 …………………………………………………………………………… 7 28 March 2005 ………………………………………………………………………… 7 26 December 2004 ……………………………………………………………………… 7 23 December 2004 ……………………………………………………………………… 8 23 May 1989 …………………………………………………………………………… 8 28 March 1964 ………………………………………………………………………… 8 22 May 1960 …………………………………………………………………………… 9 14 November 1953 ……………………………………………………………………… 13 26 August 1883 ………………………………………………………………………… 13 13 October 1874 ………………………………………………………………………… 14 15 August 1868 ………………………………………………………………………… 14 22 October 1859 ………………………………………………………………………… 16 5 February 1858 ………………………………………………………………………… 17 23 January 1855 ………………………………………………………………………… 17 31 December 1852 ……………………………………………………………………… 18 Conclusion ……………………………………………………………………………… 18 Acknowledgements ……………………………………………………………………… 18 References ……………………………………………………………………………… 19 Figure 1. Locations discussed in report ……………………………………………………… 2 Table 1. Listing of tsunami events …………………………………………………………… 20 Cover Photo: Mattingleys Beach, Bridport the site of an unusual wave event in 1953. (Photo: C Mazengarb, 2009) While every care has been taken in the preparation of this report, no warranty is given as to the correctness of the information and no liability is accepted for any statement or opinion or for any error or omission. No reader should act or fail to act on the basis of any material contained herein. Readers should consult professional advisers. As a result the Crown in Right of the State of Tasmania and its employees, contractors and agents expressly disclaim all and any liability (including all liability from or attributable to any negligent or wrongful act or omission) to any persons whatsoever in respect of anything done or omitted to be done by any such person in reliance whether in whole or in part upon any of the material in this report. Tasmanian Geological Survey Record 2009/04 3 Ab stract This report is a collation of historical accounts of unusual wave activity around the Tasmanian coastline. Sixteen events have been recorded since 1852, some of which are most likely tsunamis generated from relatively local to distant sources. The cause of some of the events recorded is uncertain. The report provides an insight into the frequency and effects of tsunamis during the period of European settlement although the record is undoubtedly incomplete and not long enough to capture the full range of potential events. Introduction This report is a compilation of European era records of given following a more recent event. It should be noted that tsunamis in Tasmania undertaken as a supplementary the word ‘tsunami’ only started being used consistently in exercise and recommended by a palaeotsunami the last 20 years or so and before that ‘tidal wave’, ‘seismic investigation of the Hobart area in 2007 (Cochran and wave’ or ‘earthquake wave’ were often used. A listing of all Wilson, 2007). The purpose of this report is to documents is provided in Table 1. systematically document references of possible tsunami events in order to gain a better understanding of their The report provides transcripts of relevant documents frequency and effects. The report represents approximately coupled with a brief summary. Key locations are provided in three months work with much of the information sourced Figure 1 and a summary chart of key findings is presented in from records kept in the State Library of Tasmania. Table 1. A summary of all references reviewed is provided in Table 1 as a way to eliminate duplication of effort by others This was largely a desktop study, supplemented by limited in the future. It must be realised that some events could field work to confirm details associated with recent events. Given the limited time available it was not possible to scan have been missed and some records are ambiguous and may all available documents. Rather, the research strategy not necessarily be true tsunamis. Therefore, while this employed was to identify key dates based on existing report provides a useful research resource for ongoing summaries such as Rynn (1994), Dominey-Howes (2007), studies, the reader must exercise caution in drawing web-based catalogues such as the National Geophysical conclusions from the supplied information. Data Centre (http://www.ngdc.noaa.gov/), and discussions Geoscience Australia define a tsunami as follows: with organisations and experts in Australia and New Zealand (listed in the Acknowledgements section). Tsunami (pron: ‘soo-nar-me’) is a Japanese word; ‘tsu’ meaning harbour and ‘nami’ meaning wave. The The reader should be aware that the accuracy of historical phenomenon is usually associated with earthquakes, reports cannot always be guaranteed. The limited scope of landslides or volcanic eruptions in, or adjacent to this report was such that it was not possible to provide oceans, and results in sudden movement of the water indications of reliability using the method employed in the column. Until recently tsunamis were called tidal waves, National Oceanic & Atmospheric Administration (NOAA) even though the event has nothing to do with tides. A catalogue. tsunami is different from a wind generated surface wave In the first years of colonial settlement news was carried on the ocean. The passage of a tsunami involves the aboard ships, and information from New Zealand, for movement of water from the surface to the seafloor example, might well travel as far as England before it was which means its speed is controlled by water depth. carried back to Tasmania. For this reason it has been Consequently, as the wave approaches land and reaches imperative to read newspapers dated up to a month or so increasingly shallow water it slows. However, the water after a given event was known to have taken place. column that is still in deeper water is moving faster and Furthermore, each newspaper had its own style of catches up, resulting in the waves bunching up and reporting. Sometimes information appeared in letters to the becoming much higher. A tsunami is often a series of editor, and at other times information of a past activity was waves and the first may not necessarily be the largest. Tasmanian Geological Survey Record 2009/04 4 Historical Accounts 30 September 2007 residents at St Helens, Spring Bay and north to Sydney were issued with a top priority immediate tsunami Nature of event bulletin. While the alert was dropped for mainland States late yesterday afternoon, it remained in place for On 30 September 2007 a magnitude 7.4 earthquake the East and South-East coasts of Tasmania, and many occurred 205 km northwest of Auckland Islands and areas reported a slight rise in sea levels. St Helens Coast 1245 km southwest of Wellington in an area known as the Guard commander Ian Hollingsworth said he had Puysegur Trench. This event generated a small tsunami that noticed a rise of about 30 cm in the sea off St Helens affected the east coast of Australia (USGS National about 5:30 pm yesterday, just when any expected rise Earthquake Information Centre, reference 1053). was predicted to occur. “We were watching the beach See Reference 16 in Table 1. over near the sea wall in Burns Bay at the entrance to St Helens,” Mr Hollingsworth said. “The tide was low at Re search sum mary the time and we noticed that it moved up to a bit under half a tide’s line for about 30 seconds. There was no sea A warning was given after the tsunami was generated running, no wave or anything like that ... so we put it 1400 km southeast of Tasmania. The tide gauge at Triabunna down to that being what it was.” However, Mr recorded fluctuations of around 200 mm. Witnesses in Hollingsworth said that if he had not been looking for St Helens, Spring Bay and Fortescue Bay recorded estimates the rise he would not have seen it. “It was hardly of approximately 300 to 350 mm (see fig. 1). noticeable’” he said. “But there was no other reason for it to lift all of a sudden like that.” While the tsunami alert ABC News, Sunday 30 September 2007 was cancelled about 8 pm yesterday, Mr Hollingsworth www.library.uq.edu.au/ssah/useits/news.html wondered how effective the alert system had been. “If you weren’t listening to the ABC (radio), you wouldn’t Tasmania’s Bureau of Meteorology has have known,” he said. “There was no alert given (to us), confirmed the effects of a small tsunami have we weren’t made aware of anything. Whereas the last been noticed around the state. one that happened...the police were made aware of it, A tsunami warning was issued mid-afternoon after a they got in touch with us and we spoke to people who large undersea earthquake off New Zealand. The were out boating and made them aware.” warning, which initially included coastal New South Wales and Victoria as well as Tasmania has been The Mercury, Monday 1 October 2007 cancelled. Senior forecaster Simon McCulloch says the Microfilm records, State Library of Tasmania effects were minimal, with swells estimated to be around 20 centimetres. He says the tsunami’s effects Tsunami alert proves barely a ripple were noticed about half an hour later than predicted.