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We present an analysis of the oldest detailed account of tsunami run-up in Indonesia, that of the 1674 Ambon tsunami (Rumphius in Waerachtigh Verhael van de Schuckelijcke Aerdbebinge, BATAVIA, Dutch East Indies, 1675). At 100 m this is the largest run-up height ever documented in Indonesia, and with over 2300 fatalities even in 1674, it ranks as one of Indonesia’s most deadly tsunami disasters. We consider the plausible sources of earthquakes near Ambon that could generate a large, destructive tsunami, including the Seram Megathrust, the South Seram Thrust, and faults local to Ambon. We conclude that the only explanation for the extreme run-up observed on the north coast of Amon is a tsunami generated by an earthquake-triggered coastal landslide. We use a two-layer tsunami model to show that a submarine landslide, with an approximate volume of 1 km³, offshore the area on Ambon’s northern coast, between Seith and Hila, where dramatic changes in coastal landscape were observed can explain the observed tsunami run-up along the coast. Thus, the 1674 Ambon tsunami adds weight to the evidence from recent tsunamis, including the 1992 Flores, 2018 Palu and Sunda Strait tsunamis, that landslides are an important source of tsunami hazard in Indonesia.
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The 1674 Ambon Tsunami: Extreme Run-Up Caused by an Earthquake-Triggered Landslide
IGNATIUS RYAN PRANANTYO
1
and PHIL R. CUMMINS
1
Abstract—We present an analysis of the oldest detailed
account of tsunami run-up in Indonesia, that of the 1674 Ambon
tsunami (Rumphius in Waerachtigh Verhael van de Schuckelijcke
Aerdbebinge, BATAVIA, Dutch East Indies, 1675). At 100 m this
is the largest run-up height ever documented in Indonesia, and with
over 2300 fatalities even in 1674, it ranks as one of Indonesia’s
most deadly tsunami disasters. We consider the plausible sources of
earthquakes near Ambon that could generate a large, destructive
tsunami, including the Seram Megathrust, the South Seram Thrust,
and faults local to Ambon. We conclude that the only explanation
for the extreme run-up observed on the north coast of Amon is a
tsunami generated by an earthquake-triggered coastal landslide. We
use a two-layer tsunami model to show that a submarine landslide,
with an approximate volume of 1 km
3
, offshore the area on
Ambon’s northern coast, between Seith and Hila, where dramatic
changes in coastal landscape were observed can explain the
observed tsunami run-up along the coast. Thus, the 1674 Ambon
tsunami adds weight to the evidence from recent tsunamis,
including the 1992 Flores, 2018 Palu and Sunda Strait tsunamis,
that landslides are an important source of tsunami hazard in
Indonesia.
Keywords: Eastern Indonesia, Ambon, tsunami hazard,
landslide.
1. Introduction
Eastern Indonesia, and the Banda Sea in particu-
lar, is a region of very active and complex tectonics
(Hamilton 1979; McCaffrey 1988; Spakman and Hall
2010; Pownall et al. 2013). Despite a historical
record rich in major, destructive earthquakes and
tsunamis, during the more recent era of instrumental
seismology most of the major events have occurred in
western Indonesia. The only way to better understand
the tsunami threat in eastern Indonesia is therefore to
glean as much information as we can from the his-
torical record, which often consists of accounts that
are sparse and difficult to interpret.
The oldest detailed tsunami account in Indonesia
was documented by Rumphius (1675). A devastating
earthquake rocked Ambon and its surrounding islands
on 17 February 1674. The earthquake was followed
by a massive tsunami about 100 m in run-up height
which was only observed on the northern coast of
Ambon Island while other areas experienced only
minor tsunamis. The earthquake and tsunami caused
more than 2300 fatalities, mostly on the northern
shore of Ambon.
The source of the tsunami and earthquake is
unknown. Løvholt et al. (2012) and Harris and Major
(2017) speculated that it was triggered by an earthquake
from south of Ambon and a landslide triggered by an
earthquake from inside Ambon Bay, respectively.
However, no attempt has been made to investigate this
event further, particularly to answer why the extreme
run-up was observed only on the northern coast of
Ambon. Therefore, the primary source of the tsunami
and earthquake remains open to question.
In the following sections of this paper, the tec-
tonic setting around Ambon is discussed first,
followed by our interpretation of the accounts of this
event. The primary source of the earthquake and
tsunami is investigated through analysis of the
Rumphius document. Tsunami modelling is then
performed to confirm the analysis. Lastly, the result
of the analysis and the implications of the findings are
discussed.
2. Tectonic Setting Around Ambon
Ambon is a small volcanic island that lies south-
west of Seram Island (Fig. 1). It consists of two small
1
Research School of Earth Sciences, Australian National
University, Canberra, Australia. E-mail: ryan.pranantyo@anu.edu.
au; phil.cummins@anu.edu.au
Pure Appl. Geophys. 177 (2020), 1639–1657
Ó2019 Springer Nature Switzerland AG
https://doi.org/10.1007/s00024-019-02390-2 Pure and Applied Geophysics
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... Such new data and findings in eastern Indonesia provide the opportunity to further develop the current understanding of regional tsunami hazards. Pelinovsky et al. (1997); Pranantyo and Cummins (2019b); volcanic tsunamis are taken from Paris et al. (2013); SMF tsunami is from Pranantyo and Cummins (2019a), whereas SMF scarps are from Brune et al. (2009bBrune et al. ( , 2009aBrune et al. ( , 2010; Watkinson and Hall (2017); Pownall et al. (2016); Brackenridge et al. (2020) and. FBT Flores Back-arc Thrust, BD Banda Detachment, PKF Palu-Koro Fault, WD Weber Deep, SMF Submarine Mass Failure ...
... The JAGURS code has been widely used to study and validate modern historical events, such as the 2011 Tohoku, Japan (Baba et al. 2015(Baba et al. , 2017, the 2015 Illapel, Chile (Williamson et al. 2017), and the 1992 Flores, Indonesia (Pranantyo and Cummins 2019b) tsunamis. Moreover, the code was also used to investigate historical events prior to the instrumental period: the 1674 Ambon Island (Pranantyo and Cummins 2019a) and the 1852 Banda Sea events. ...
... , do not neccesarily include detailed information for each event. For example,Pranantyo and Cummins (2019a) hypothesised a coastal landslide as the main source of the 1674 Ambon tsunami after re-analysing historical accounts. As another example, instead of the Tanimbar Trough megathrust earthquake (Fisher and Harris 2016),Cummins et al. (2020) suggested a moderate earthquake on the Banda Detachment triggered an SMF to generate the devastating 1852 Banda Sea tsunami event. ...
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