Yes, a tsunami could hit Sydney – causing flooding and dangerous currents



File 20181014 109207 1cee72t.jpg?ixlib=rb 1.1
Manly’s The Corso pedestrian area could be flooded if a large tsunami arrived at Sydney Harbour.
from www.shutterstock.com

Kaya Wilson, University of Newcastle and Hannah Power, University of Newcastle

Sulawesi’s recent tsunami is a striking reminder of the devastating, deadly effects that the sudden arrival of a large volume of water can have.

Published today, our new research shows what might happen if a tsunami hit Sydney Harbour. A large tsunami could cause significant flooding in Manly. Even very small waves might result in dangerous currents in the entrance of the Harbour and in narrow channels such as at the Spit Bridge.

Beyond Sydney, large areas of the east coast of Australia would also be affected.




Read more:
Making waves: the tsunami risk in Australia


Our study considered a range of tsunamis, with heights ranging from just 5cm to nearly 1.5m when measured outside the Heads of Sydney Harbour. These wave heights sound small, but because the wavelengths of tsunami are so long (tens to hundreds of kilometres), these waves contain a very large mass of water and can be incredibly powerful and destructive. Wave heights also increase as the tsunami encounters shallower water.

A tsunami generated by an earthquake off Chile in 1960 created waves that reached Australia..
NSW Office of Environment and Heritage holdings

How a tsunami might happen

Most tsunamis are caused by earthquakes at sea, where a shift in the sea floor creates the sudden movement of a large volume of water.

Our study approach involved modelling the likely effects of different-sized tsunamis generated by earthquakes on the New Hebrides trench to the northeast (in line with the Vanuatu islands) and the Puysegur trench (south of New Zealand).

For each event we assigned Average Recurrence Intervals (ARI), which provide an average indication of how often tsunamis of different sizes are likely to occur.

The tsunamis we studied range from an ARI of 25 years to 4,700 years. The tsunami with an ARI of 4,700 had a wave height of 1.4m outside the Heads and is the largest tsunami we could reasonably expect in Sydney Harbour. An event with an ARI of 4,700 can also be considered as an event with a 1.5% chance of occurring over a 70-year lifetime.

What would the tsunami look like?

The tsunamis we’d expect to see in Sydney Harbour would be a sequence of waves with about 15-40 minutes on average between each peak. Some waves might break, and others might appear as a rapid rising and falling of the water level.

The highest water levels would depend on the tide and the size of the event – the largest events could raise the water level up to several metres higher than the predicted tide levels.

The visualisation below represents a tsunami in a fictional location, and shows the rise and fall of water levels (with time sped up).

Tsunami visualisation in a fictitious location (created by the IT Innovation team at the University of Newcastle).

What area is at highest risk?

A tsunami is not just one single wave, but generally a sequence of waves, lasting hours to days. Within the Harbour, larger waves are most likely to breach land, and high tide increases the risk.

The narrow part of Manly – where The Corso part-pedestrian mall is located – is one of the most exposed locations. The largest tsunamis we could expect may flood the entire stretch of The Corso between the open ocean and the Harbour.

The low-lying bays on the southern side of the Harbour could also be affected. A tsunami large enough to flood right across Manly is estimated to have a minimum ARI of 550 years, or at most a 12% chance of occurring over an average lifetime.

Maximum inundation estimated to occur for a tsunami sourced from a 9.0Mw earthquake at the Puysegur trench.
Kaya Wilson, Author provided

Examining these worst-case scenarios over time shows how this flooding across Manly may occur from both the ocean side and the harbour side, isolating North Head.

Maximum inundation estimated to occur for a tsunami sourced from a 9.0Mw earthquake at the Puysegur trench and an animation showing the arrival of this tsunami at high tide. Each frame of the animation represents a two minute time interval.



Read more:
An Indonesian city’s destruction reverberates across Sulawesi


How fast would a tsunami move?

Even though the smaller tsunamis may not flood the land, they could be very destructive within the Harbour itself. Our modelling shows the current speeds caused by smaller tsunamis have the potential to be both damaging and dangerous.

The map below shows the maximum tsunami current speeds that could occur within the Harbour for the largest event we could reasonably expect.

Maximum current speeds estimated to occur for a tsunami sourced from a 9.0 magnitude earthquake at the Puysegur trench.
Kaya Wilson, Author provided

Areas exposed to the open ocean and locations with a narrow, shallow channel – such as those near the Spit Bridge or Anzac Bridge – would experience the fastest current speeds. A closer look at the area around the Spit Bridge, shows how even smaller tsunamis could cause high current speeds.

The animation below shows a comparison between the current speeds experienced during a regular spring high tide and those that may occur if a tsunami generated by a 8.5 magnitude earthquake on the New Hebrides trench coincided with a spring high tide. A tsunami of this size (0.5m when outside the Harbour) has been estimated to occur once, on average, every 110 years (a 47% chance of occurring over a lifetime).

Current Speed animation and maximum current speeds expected to occur at the Spit Bridge for a tsunami sourced from a 8.5MW earthquake at the New Hebrides trench. Each frame of the animation represents a 2 minute time interval.

This video below shows similar current speeds (7m/s based on video analysis) when the Japanese tsunami of 2011 arrived in the marina in Santa Cruz, California, and caused US$28 million of damage.

A small, fast-moving wave can have a huge impact.

Historical records show us what happened when a tsunami generated by an earthquake off Chile reached Sydney Harbour in 1960. We didn’t have any instruments measuring current speeds then, but we have witness accounts and we know that many ships were ripped from their moorings.

Fort Denison tide gauge records of the 1960 Chilean tsunami in Sydney Harbour.
NSW Office of Environment and Heritage holdings

A whirlpool and significant erosion was also reported in the Spit Bridge area. Photographs from the time show just how much sand was washed away at Clontarf Beach.

Clontarf beach erosion: (Left) 2014 in usual sediment conditions and (right) 1960 post tsunami.
Northern Beaches Council holdings

How to stay safe

A large tsunami affecting Australia is unlikely but possible. Remember that tsunamis are a sequence of waves that may occur over hours to days, and the biggest wave in the sequence could occur at any time.

The Joint Australian Tsunami Warning Centre (JATWC), jointly operated by Geoscience Australian and the Bureau of Meteorology, provides a tsunami warning system for all of Australia.

Warnings when issued are broadcast on radio and television, through the Bureau of Meteorology Tsunami warning centre and on twitter (@BOM_au).

State Emergency Services are trained to respond to a tsunami emergency and there are online resources that can help communities with awareness and preparation.


The bathymetry compilations used by this research are publicly available and can be viewed as a publication with links for free download.The Conversation

Kaya Wilson, PhD Candidate, University of Newcastle and Hannah Power, Senior Lecturer in Coastal Science, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Why Indonesia’s tsunamis are so deadly



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MAST IRHAM/EPA

Anja Scheffers, Southern Cross University

The magnitude 7.5 earthquake, and subsequent tsunami, that struck Indonesia days ago has resulted in at least 1,200 deaths.

Authorities are still gauging the extent of the damage, but it’s clear the earthquake and tsunami had a devastating effect on the Sulawesi region, particularly the city of Palu.

It’s not the first time earthquakes have caused mass destruction and death in Indonesia. The tsunamis that follow are particularly damaging. But why?

A combination of plate tectonic in the region, the shape of the coastline, vulnerable communities and a less-than-robust early warning system all combine to make Indonesian tsunamis especially dangerous.




Read more:
Would a better tsunami warning system have saved lives in Sulawesi?


Tectonic plates

Indonesia covers many complex tectonic environments. Many details of these are still poorly understood, which hampers our ability to predict earthquake and tsunami risks.

The biggest earthquakes on Earth are “subduction zone” earthquakes, which occur where two tectonic plates meet.

In December 2004 and March 2005, there were a pair of subduction zone earthquakes along the Sunda Trench offshore of the west coast of Sumatra. In particular, the magnitude-9.1 quake in December 2004 generated a devastating tsunami that killed almost a quarter of a million people in countries and islands surrounding the Indian Ocean.

But only looking out for these kinds of earthquakes can blind us to other dangers. Eastern Indonesia has many small microplates, which are jostled around by the motion of the large Australia, Sunda, Pacific and Philippine Sea plates.

The September quake was caused by what’s called a “strike-slip” fault in the interior of one of these small plates. It is rare – although not unknown – for these kinds of quakes to create tsunamis.

The fault systems are rather large, and through erosion processes have created broad river valleys and estuaries. The valley of the Palu river, and its estuary in which the regional capital Palu is located, have been formed by this complex fault system. Studies of prehistoric earthquakes along this fault system suggests this fault produces magnitude 7-8 earthquakes roughly every 700 years.

The sea floor shapes the wave

Another important factor for tsunamis is the depth and shape of the sea floor. This determines the speed of the initial waves. Strong subduction zone earthquakes on the ocean floor can cause the entire ocean water column to lift, then plunge back down. As the water has momentum, it may fall below sea level and create strong oscillations.

The bulge of water moving outward from the centre of a earthquake maybe of limited height (rarely much more than a metre), but the mass of water is extremely large (depending on the surface area moved by the earthquake).

Tsunami waves can travel very fast, reaching the speed of a jet. In water 2km deep they can travel at 700km per hour, and over very deep ocean can hit 1,000km per hour.

When the wave approaches the shallower coast, its speed decreases and the height increases. A tsunami may be 1m high in the open ocean, but rise to 5-10m at the coast. If the approach to the shoreline is steep, this effect is exaggerated and can create waves tens of metres high.

Despite the fact that the waves slow down near the coast, their immense starting speeds mean flat areas can be inundated for kilometres inland. The ocean floor topography affects the speed of tsunami waves, meaning they move faster over deep areas and slow down over submarine banks. Very steep land, above or below water, can even bend and reflect waves.

The coastlines of the Indonesian archipelago are accentuated, in particular in the eastern part and especially at Sulawesi. Palu has a narrow, deep and long bay: perfectly designed to make tsunamis more intense, and more deadly.

This complex configuration also makes it very difficult to model potential tsunamis, so it’s hard to issue timely and accurate warnings to people who may be affected.




Read more:
Explainer: after an earthquake, how does a tsunami happen?


Get to high ground

The safest and simplest advice for people in coastal areas that have been affected by an earthquake is to get to higher ground immediately, and stay there for a couple of hours. In reality, this is a rather complex problem.

Hawaii and Japan have sophisticated and efficient early warning systems. Replicating these in Indonesia is challenging, given the lack of communications infrastructure and the wide variety of languages spoken throughout the vast island archipelago.

After the 2004 Indian Ocean disaster, international efforts were made to improve tsunami warning networks in the region. Today, Indonesia’s tsunami warning system operates a network of 134 tidal gauge stations, 22 buoys connected to seafloor sensors to transmit advance warnings, land-based seismographs, sirens in about 55 locations, and a system to disseminate warnings by text message.

However, financing and supporting the early warning system in the long term is a considerable problem. The buoys alone cost around US$250,000 each to install and US$50,000 annually for maintenance.

The three major Indonesian agencies for responsible for earthquake and tsunami disaster mitigation have suffered from budget cuts and internal struggles to define roles and responsibilities.

Lastly, the Palu tsunami event has highlighted that our current tsunami models are insufficient. They do not properly consider multiple earthquake events, or the underwater landslides potentially caused by such quakes.

No early warning system can prevent strong earthquakes. Tsunamis, and the resulting infrastructure damage and fatalities, will most certainly occur in the future. But with a well-developed and reliable early warning system, and better communication and public awareness, we can minimise the tragic consequences.

With earthquakes that occur very close to the beach – often the case in Indonesia – even an ideal system could not disseminate the necessary information quickly enough. Indonesia’s geography and vulnerable coastal settlements makes tsunamis more dangerous, so we need more and concerted efforts to create earthquake and tsunami resilient communities.The Conversation

Anja Scheffers, Professor, Southern Cross University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Would a better tsunami warning system have saved lives in Sulawesi?


Jane Cunneen, Curtin University

The death toll from the magnitude 7.5 earthquake and resulting tsunami that struck near Palu, Indonesia, on Friday evening continues to rise, with several regions yet to be reached by rescue teams.

But the size and location of the earthquake should not have come as a surprise. Palu is situated at the end of a long, narrow bay which is the surface expression of a very active fault, the Palu-Koro fault.

The area is at high risk of tsunami, with several large earthquakes and tsunamis occurring along the fault within the past 100 years.




Read more:
Explainer: after an earthquake, how does a tsunami happen?


Details of Friday’s incident are limited, but already there are questions being asked about the effectiveness of Indonesia’s tsunami warning system.

It was developed after the devastating 2004 Boxing Day tsunami that occurred after an earthquake near Sumatra, but in this recent event the warning did not reach many of the people who were affected.

The tsunami occurred in an area where there are no tide gauges that could give information about the height of the wave. There are reports that a more high-tech system could have saved lives if it had been fully implemented.

Most of Indonesia’s deep ocean tsunameter buoys, specially designed to detect tsunamis in the open ocean, have not been working since 2012.

The Indonesian Tsunami Warning System issued a warning only minutes after the earthquake, but officials were unable to contact officers in the Palu area. The warning was cancelled 34 minutes later, just after the third tsunami wave hit Palu.

Tsunami history of Palu

Large earthquakes are not uncommon in Palu, with 15 events over magnitude 6.5 occurring in the past 100 years. The largest was a magnitude-7.9 event in January 1996, about 100km north of Friday’s earthquake.

Several these large earthquakes have also generated tsunamis. In 1927, an earthquake and tsunami caused about 50 deaths and damaged buildings in Palu. In 1968 an earthquake with magnitude 7.8 near Donggala generated a tsunami wave that killed more than 200 people.

Despite this history, many people in Palu were not aware of the risk of a tsunami following the earthquake. Ten years on from the 2004 Boxing Day tragedy that killed at least 226,000 people, there were concerns about tsunami warning systems across the region.

An advanced warning system currently only in the prototype stage may not have helped the people of Palu, as the tsunami struck the shore within 20 minutes of the earthquake.

Such early warning systems are most useful for areas several hundred kilometres from the tsunami source. In regions like Palu where the earthquake and tsunami source are very close, education is the most effective warning system.

It is not yet clear whether Friday’s tsunami was caused by movement on the fault rupture from the earthquake, or from submarine landslides within Palu bay caused by the shaking from the earthquake.

The sides of the bay are steep and unstable, and maps of the sea floor suggest that submarine landslides have occurred there in the past.

If the tsunami was generated by a submarine landslide within the bay, tsunami sensors or tide gauges at the mouth of the bay would not have sensed the tsunami wave before it struck the shore in Palu.

Communication networks

High tech tsunami warning systems are able to send out warnings through phone networks and other communications channels, and reach the community through text messages and tsunami sirens on the beaches.

But in areas where a devastating earthquake has occurred, this infrastructure is often too damaged to operate and the warning messages simply can’t get through. In Palu, the earthquake destroyed the local mobile phone network and no information was able to get in or out of the area.

Timing is also crucial. Official tsunami warnings require analysis of data and take time – even if it is only minutes – to prepare and disseminate.

This time is crucial for people near the earthquake epicentre, where the tsunami may strike within minutes of the earthquake. Those living in such areas need to be aware of the need to evacuate without waiting for official warnings, relying on the earthquake itself as a natural warning of a potential tsunami.




Read more:
Be prepared, always: the tsunami message from New Zealand’s latest earthquake


The need to raise awareness of the risk becomes even more challenging when large tsunamis occur infrequently, as in Palu. Many residents would not have been born when the last tsunami impacted the town in 1968.

So high tech warning systems may not be effective in areas close to the earthquake epicentre. Ongoing awareness and education programmes are the most important part of a tsunami warning system in coastal areas at risk of tsunami, no matter how infrequently they occur.The Conversation

Jane Cunneen, Research Fellow, Curtin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Two types of tectonic plate activity create earthquake and tsunami risk on Lombok


Jane Cunneen, Curtin University and Phil R. Cummins, Australian National University

Several large earthquakes have struck the Indonesian island of Lombok in the past week, with the largest quake killing at least 98 people and injuring hundreds more.

Thousands of buildings are damaged and rescue efforts are being hampered by power outages, a lack of phone reception in some areas and limited evacuation options.

The majority of large earthquakes occur on or near Earth’s tectonic plate boundaries – and these recent examples are no exception. However, there are some unique conditions around Lombok.

The recent earthquakes have occurred along a specific zone where the Australian tectonic plate is starting to move over the Indonesian island plate – and not slide underneath it, as occurs further to the south of Lombok.

This means there is earthquake and tsunami risk not only along the plate boundary south of Lombok and Bali, but also from this zone of thrusting to the north.




Read more:
Bali’s Agung – using ‘volcano forensics’ to map the past, and predict the future


Jammed subduction zone

Tectonic plates are slabs of the Earth’s crust that move very slowly over our planet’s surface. Indonesia sits along the “Pacific Ring of Fire” where several tectonic plates collide and many volcanic eruptions and earthquakes occur.

Some of these earthquakes are very large, such as the magnitude 9.1 quake off the west coast of Sumatra that generated the 2004 Indian Ocean tsunami. This earthquake occurred along the Java-Sumatra subduction zone, where the Australian tectonic plate moves underneath Indonesia’s Sunda plate.

But to the east of Java, the subduction zone has become “jammed” by the Australian continental crust, which is much thicker and more buoyant than the oceanic crust that moves beneath Java and Sumatra.

The Australian continental crust can’t be pushed under the Sunda plate, so instead it’s starting to ride over the top of it. This process is known as back-arc thrusting.

The data from the recent Lombok earthquakes suggest they are associated with this back-arc zone. The zone extends north of islands stretching from eastern Java to the island of Wetar, just north of Timor (as shown in map below).

Earthquake hazards along plate boundaries near Indonesia. The dates in the map show historical earthquakes, and Mw indicates earthquake magnitude.
Edited by P. Cummins from an original by Koulali and co-authors

Historically, large earthquakes have also occurred along this back-arc thrust near Lombok, particularly in the 19th century but also more recently. (Dates and sizes of past earthquakes are shown in the map above).

It is thought that this zone of back-arc thrusting will eventually form a new subduction zone to the north along from eastern Java to the island of Wetar just north of Timor.




Read more:
I’ve always wondered: do nuclear tests affect tectonic plates and cause earthquakes or volcanic eruptions?


Tsunami risk

Lombok’s recent earthquakes – the August 5 6.9 magnitude quake plus a number of aftershocks, and the 6.4 magnitude earthquake just a week before it – occurred in northern Lombok under land, and were quite shallow.

Recent earthquakes on Lombok were also felt on the neighbouring island of Bali.
US Geological Survey

Earthquakes on land can sometimes cause undersea landslides and generate a tsunami wave. But when shallow earthquakes rupture the sea floor, much larger and more dangerous tsunamis can occur.

Due to the large number of shallow earthquakes along the plate boundaries, Indonesia is particularly vulnerable to tsunamis. The 2004 Indian Ocean tsunami killed more than 165,000 people along the coast of Sumatra, and in 2006 over 600 people were killed by a tsunami impacting the south coast of Java.




Read more:
Explainer: after an earthquake, how does a tsunami happen?


The region around Lombok has a history of tsunamis. In 1992 a magnitude 7.9 earthquake occurred just north of the island of Flores and generated a tsunami that swept away coastal villages, killing more than 2,000.

Nineteenth century earthquakes in this region also caused large tsunamis that killed many people.

The areas around Lombok and the islands nearby, including Bali, are at high risk for earthquakes and tsunamis occurring both to the north and the south of the island.

The ConversationUnfortunately, large earthquakes like the ones this week cannot be predicted, so an understanding of the hazards is vital if we are to be prepared for future events.

Jane Cunneen, Research Fellow, Curtin University and Phil R. Cummins, Professor, Australian National University

This article was originally published on The Conversation. Read the original article.

What happened in New Zealand’s magnitude 7.5 earthquake


Brendan Duffy, University of Melbourne and Mark Quigley, University of Melbourne

At least two people have died in the magnitide 7.5 earthquake that struck New Zealand’s South Island early on Monday, local time.

Preliminary modelling suggests that the earthquake was caused by a rupture of a northeast-striking fault that projects to the surface offshore.

But this may be a complex event, involving several faults on the South Island.

The northern part of the South Island straddles the boundary between the Pacific and Australian tectonic plates.

The jostling between these plates pushes up rocks that create mountains including the Southern Alps and the beautiful Seaward Kaikoura Range, one of New Zealand’s most rapidly uplifting mountain ranges.

The plate motion forces the oceanic crust of the Pacific plate beneath the Australian plate on thrust faults, and also causes the plates to slide laterally with respect to one another on strike-slip faults.

The region affected by the recent earthquake has been one of the most seismically active in New Zealand over the past few years, including earthquakes that occurred as part of the Cook Strait earthquake sequence in 2013. It is likely that these sequences are related given their close spatial and temporal association.

What slipped during the earthquake?

The preliminary analysis strongly suggests that most of the energy release during this earthquake was sourced from the rupture of a roughly 200km-long fault system. This fault system is aligned northeast and dips to the northwest, beneath the northern part of the South Island. It coincides roughly with the subduction thrust in this area.

The potential for large earthquakes on the subduction fault in the lower North Island and upper South Island of New Zealand was recently highlighted by GNS Science, New Zealand’s geological survey. It published evidence for two similar events in the Blenheim area roughly 520-470 years ago, and 880-800 years ago.

Given its setting, this latest earthquake may be structurally complex, involving a mixture of plate boundary thrusting, lateral slip on strike-slip faults, and thrusting within the Pacific plate close to the epicentre, some 15km northeast of Culverden.

The largest aftershocks suggest a mixture of thrusting and strike-slip movements.

The damage caused by the earthquake

Because the fault system was large, and the earthquake apparently started at the southwest end of the fault and propagated to the northeast, the seismic energy was released over a period of up to two minutes.

Large earthquakes produce more long period wave energy than smaller events. The 2011 Christchurch earthquake contained a lot of high-frequency energy and very strong ground accelerations, exposing more than 300,000 people to very strong to intense ground shaking.

In contrast, this recent earthquake was manifested in Christchurch as lower-frequency rolling, and due to the sparse population density in the earthquake region, roughly 3,000 people in the upper South Island experienced strong ground shaking equivalent to the Christchurch earthquake.

Reports are emerging of at least one major fracture in the ground surface that could be related to strike-slip faulting in the Clarence region.

More traces may yet be found given the complexity of the earthquake. Tide gauge analysis will help to understand if a similar trace offshore caused the tsunami.

The earthquake has also triggered liquefaction in coastal areas and in susceptible sediments, and landsliding of up to a million cubic metres along steep susceptible cliffs in the northern South Island.

There are reports of extensive road damage including in the area between Hanmer Springs and Culverden, much of State Highway 1 and even Wellington, on the North Island.

Most of this damage is probably caused by strong ground shaking, which causes weak ground to move en masse and has resulted in numerous slips and road closures in the central and northern South Island.

Earthquakes, aftershocks and the pull of the moon

Given the earthquake happened on the eve of a supermoon full moon, and the closest the Earth and moon will be since 1948, it wasn’t long before some tried to make a connection.

But the tidal triggering of earthquakes has been investigated since the 19th century and remains a challenging and controversial field.

Small amplitude and large wavelength tidal deformations of the Earth due to motions of the sun and moon influence stresses in Earth’s lithosphere.

It is possible that, for active faults that are imminently close to brittle failure, small tidal force perturbations could be enough to advance rupture relative to the earthquake cycle, or to allow a propagating rupture to travel further than it might otherwise have done.

But the specific time, magnitude and location of this or any other large earthquake has not been successfully predicted in the short-term using tidal stresses or any other possible precursory phenomenon.

Deliberately vague predictions that provide no specific information about the precise location and magnitude of a future earthquake are not predictions at all. Rather, these are hedged bets that get media air time due to the romantic misinterpretation that they were valid predictions.

Most earthquake scientists, including those that research tidal triggering of earthquakes, highlight the importance of preparedness over attempts at prediction when it comes to public safety.

To this end, GNS Science uses a system of operational earthquake forecasts to communicate earthquake risk to concerned New Zealand residents during an aftershock sequence such as we are now entering.

These forecasts are based on earthquake physics and statistical seismology. The current operational forecast indicates an 80% probability of:

A normal aftershock sequence that is spread over the next few months. Felt aftershocks (e.g. M>5) would occur from the M7.5 epicentre near Culverden, right up along the Kaikoura coastline to Cape Campbell over the next few weeks and months.

This aftershock sequence will probably (98%) include several large aftershocks (some greater than magnitude 6 have already occurred), and for each magnitude 6 aftershock we expect 10 more magnitude 5 aftershocks over the coming days and weeks.

The Conversation

Brendan Duffy, Lecturer in Applied Geoscience, University of Melbourne and Mark Quigley, Associate professor, University of Melbourne

This article was originally published on The Conversation. Read the original article.

Japan: Two Years On from Devastating Earthquake and Tsunami


The link below is to an article (with photos) that looks at Japan two years on from the devastating earthquake and tsunami.

For more visit:
http://www.theatlantic.com/infocus/2013/03/japan-earthquake-2-years-later-before-and-after/100469/

Indonesia: Aceh – Major Earthquake & Tsunami Warning


The following article reports on a massive earthquake off Aceh in Indonesia. The earthquake measured 8.7 and tsunami warnings have been issued around the Indian Ocean.

http://www.abc.net.au/news/2012-04-11/strong-quake-strikes-off-aceh/3944352