GeoLog

These are the outwash plains for the Icelandic volcano, Katla:

“Sandstorm, Myrdalssandur outwash plain, Iceland” by Ragnar Th Sigurdsson. This image is distributed by the European Geosciences Union under a Creative Commons licence.

An outwash plain (or sandur) is a broad, shallowly sloping region ahead of a glacial front. They are made up of material that has been deposited by glacial meltwater, released either by geothermal heating or a subglacial eruption. The extensive volcanism and abundance of ice-capped volcanoes in southern Iceland means that the outwash plains are particularly well developed here.

The Mýrdalssandur outwash plain in relation to the volcano Katla (Mýrdasljökull) [source: Jóhannesdóttir and Gísladóttir, 2010].

Between flooding events, some vegetation takes hold, but much of the soil is loose and easily transported by wind. Indeed, the soil islands you see in the photo are formed by wind-blown soil and if they were to erode, the area would be a desert consisting of glacial alluvial sediments alone. Sandstorms, such as the one above, carry fine particulate matter (clays and glacial till) from the outwash plains to other areas and even contribute to the particulate pollution in Reykjavík, some 110 km away!

References:

Jóhannesdóttir, G. and Gísladóttir, G.: People living under threat of volcanic hazard in southern Iceland: vulnerability and risk perception, Natural Hazards Earth System Science, 10, 407-420, doi:10.5194/nhess-10-407-2010, 2010.

Thorsteinsson, T., Gísladóttir, G., Bullard, J. and McTainsh, G.: Dust storm contributions to airbourne particulate matter in Reykjavík, Iceland, Atmospheric Environment, 45, 5924-5933.

Warner, N.H.: Catastrophic outwash plains on Earth and Mars: comparisons from Iceland and Chasma Boreale, Mars. PhD thesis, Arisona State University, December, 2008.

You can find more Arctic images from Ragnar Th Sigurdsson here, and more from the Imaggeo open access database here.

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their images to this repository and since it is open access, these photos can be used by scientists for their presentations or publications as well as by the press and public for educational purposes and otherwise. If you submit your images to Imaggeo, you retain full rights of use, since they are licenced and distributed by EGU under a Creative Commons licence.

Effective responses to natural disasters require the rapid acquisition of information about where has been affected, how many people are in the affected areas and what the magnitude of the damage is. This information is critical in both disaster and emergency rescue management. Indeed, the first three days after the onset of a disaster has been dubbed the “72-hour golden rescue period”, after which the survival rate of victims sharply declines. With this in mind, the need for rapid data collection could not be more evident.

Aerial photography is a useful tool in determining which areas have been affected by an earthquake, but resolution may not always be adequate to determine the damage to buildings and infrastructure within them. For this, satellite technology provides a helping hand. For example, the spectral characteristics of a building can be used to determine whether or not it has been structurally damaged. There is, however, a time delay associated with gathering and analysing satellite data and it is ineffective for more minor quakes. More importantly though, these tools provide no indication of the number of people affected within these areas beyond the assumed population density (affected rural land is likely to have fewer people immediately at risk than in an affected urban area).

Building collapse as a result of the 1995 Hanshin-Awaji earthquake [Source: Wikimedia Commons].

This is where Dr Jing Hai Xu and his team come in, as they have developed a method of using text messages to report and disseminate disaster information and Geographic Information Systems (GIS) to analyse and extract details relevant to search and rescue teams.

The network is separated into country level, provincial level, and city level, with the smallest components being streets within a town or city. One reporter is enough to include the impact on a particular location in the disaster information network. One downside of the model, though, is that the reporters need to be formal local government employees. Whilst this measure is proposed to increase the reliability of reports, it vastly reduces the number of people that can feed into the network. Perhaps an alternative way of addressing the problem of reliability would be to only include information in the network after multiple reports of a similar incident are received from the same area. Here we are faced with new problems: what constitutes one area? Will reports of the same event from different observers be sufficiently similar to be picked up in the network? This also requires the contact details of the disaster network to be disseminated to a greater proportion of the population… perhaps Xu et al.’s approach is an effective one after all!

Now that that’s decided – how does it work? Principally, there are two kinds of nodes that help the network function: 1) edge nodes, these are the people responsible for reporting disaster information, and 2) central nodes, which correspond to the central earthquake office within each city and are responsible for collecting and disseminating information. After an earthquake, the city earthquake office (central node) contacts the reporters (edge nodes), asking for information about the impact of the disaster where they are. This information is fed back to the office and these central nodes pass the information on to the provincial offices and then on to the country’s government office so that appropriate action can be taken.

Having a simple code for different impacts helps collate useful information. In this model, the first number indicates the type of damage (e.g. 4 for damage to buildings) and the second indicates the severity (with 1 being low severity and 5 being high). So the code for a few damaged buildings would be 42, or 44 for a large quantity of damaged buildings, with some partially collapsed, etc. Here are the other codes:

Earthquake disaster information codes (click to enlarge), [modified from Xu et al., 2013].

Disaster information distribution (level of shaking) from the 2012 Yangzhou earthquake, [modified from Xu et al., 2013].

So there you have it – the key to disaster management success: send an SMS.

By Sara Mynott

Reference:

Xu, J. H., Nie, G. Z., and Xu, X.: A digital social network for rapid collection of earthquake disaster information, Nat. Hazards Earth Syst. Sci., 13, 385-394, doi:10.5194/nhess-13-385-2013, 2013

In this month’s Geoscience’s column, Sara Mynott discusses the geological hazards associated with climate warming and how recent research sheds new light on our understanding of rockfall frequency.

Rockfalls are the free-falling movement of bedrock material from a rock face, a phenomenon also encompassed by the terms ‘landslide’, ‘rockslide’ and ‘rock avalanche’. They range from small debris falls of only a few cubic-metres to large ‘bergsturz’ events of over 1 million metres-cubed. The number of rockfalls reported has increased in recent years and is often attributed to global warming, despite the lack of research in this area. The debate among scientists regarding the effect of climate change on geomorphic hazards has led to a lot of confusion among the media and hence, the public.

Climate change is expected to have numerous consequences for natural hazards and the IPCC has predicted that geomorphic hazards will increase in alpine regions as a result. However, recent research published in Natural Hazards and Earth Systems Science suggests that this may not be the case. In a recent assessment of Austrian rockfalls over the period 1990-2010, Oliver Sass and Manfred Oberlechner investigated how temperature influences their frequency. Their dataset was compiled from events that were large enough to be recorded in the media, restricting it to events that have the capacity to affect people and/or infrastructure. The Huben rockslide that occurred in 1999, which resulted in both the loss of alpine road access and the destruction of a local sawmill, presents one such example.

Rockfall in Huben, Austria, that occurred on 11 March 1999, far below the permafrost limit. This rockfall resulted in both the destruction of a sawmill and loss of road access (Source: Sass and Oberlechner, 2012).

Historical records of rockfalls are scarce, making predictions for the future a challenge and, until recently, little research on the temporal frequency of rockfall events had been carried out. This is partly due to the research focus on areas of permafrost, which cover less than 4 % of the Austrian Alps. Consequently, the relationship between surface temperature and rockslide frequency in permafrost regions is well-known. Permafrost, which exists at sub-zero temperatures, cements sediment together and gives it stability. Unsurprisingly, warming causes permafrost to degrade, leading to a loss of sediment stability and an increased risk of geomorphic hazards. The likelihood of these hazards occurring is a function of substrate type. However, areas of public interest (those with infrastructure) tend to be permafrost-free. In fact, 91% of the events studied were below the permafrost limit (less than 2100 m elevation).

Contrary to the IPCC’s predictions, the study found that there was no relationship between temperature and the number of rockfall events below the permafrost limit, nor was there any correlation between precipitation and rockfall frequency. The increasing settlements and infrastructure within the Alps means there is a greater risk of a geomorphic hazard occurring and the increase in availability of information means there appears to be more events than 20 years ago. Thus, the apparent increase in rockfall occurrence in recent years is likely to be due to a reporting bias.

Whilst there is no evidence for warming increasing the annual number of rockfalls, changes in seasonal weather patterns have resulted in a shift in their occurrence throughout the year. Rockfalls are generally more common in spring than at any other time of year as both the increase in water supply (through snowmelt and high precipitation rates) and high degree of freeze-thaw activity (also known as cryoturbation) destabilises the sediment. However, in recent decades, a greater proportion of rockfalls have occurred during the summer months, leading to a more even distribution of these hazards throughout the year.

Below the permafrost limit there is insufficient evidence to support the notion that increasing rockfall events are associated with climate warming. In fact, the study reveals that milder winters may even reduce the number of rockfalls outside areas of permafrost. Whilst Sass emphasises that these results are preliminary, they highlight the complexity of predicting the impacts of climate change and expose an alternative way in which it can affect hazardous earth processes.

By Sara Mynott, EGU Communications Officer

A French and Algerian study team seeks markers of underwater earthquakes off the Algerian coast. The team also matched the site’s paleoseismic history to land-based historical reports. Wayne Deeker reports.

The Mediterranean Sea represents the boundary between the African and Eurasian plates. Yet the fault segment off the Algerian coast is one of the most active in the western Mediterranean. It is associated with a series of moderate to large earthquakes: about 22 magnitude 6+ events since 856 CE. According to historical records, very large events in Algeria have been rare, though approximately one third of documented earthquakes would have been Mw 7+.

One of the most destructive was also the most recent. In May 2003, the Algerian coast experienced a Mw 6.8 earthquake, centred on the town of Boumerdès. It killed more than 2,300 people, injured some 10,000, and did all the usual structural damage earthquakes do in such countries. It also caused a tsunami which affected the western Mediterranean.

Building damage in the city of Boumerdes, Algeria (Credit: Ali Nour CGS; National Center of Applied Research in Earthquake Engineering)

The authors of a 2012 study published in EGU’s Open Access journal Natural Hazards and Earth System Sciences wanted to understand more about this event and earthquake recurrence intervals in the area. They found interesting clues deep underwater, where the quake likely caused landslides that resulted in almost 30 breaks of submarine telecommunications cables.

The researchers say it is especially worthwhile to investigate earthquake threats in areas that, like those surrounding the Algerian fault, have irregular, long-recurrence patterns because people there will be less prepared than where earthquakes are frequent. Another good reason motivates this research. While 2003 was a very well documented earthquake, most studies of its impact were conducted on land, with little attention paid to the effects and signatures offshore. This is unsurprising, as submarine earthquakes are difficult to monitor in real time, especially during catastrophic events. Therefore, the seafloor signatures of such events have remained elusive because they are occasional, erosive, and are a complex combination of many processes.

The damage to Algerian submarine telecommunications cables provides a clue to what happened underwater in 2003. While cable breaks often denote a definite time and place, pinpointing an event which can be interpreted in context with the landscape, the 2003 breaks were vague in all but one case. The location of the recovered cables also did not correspond to the point of damage, which suggests erosive action of turbidity currents (streams of rapidly moving sediment-rich water that deposit to form so-called turdibite sedimentary beds). Satellite images confirmed this, yet the flow pattern must have been quite complex, apparently following different paths along the underwater scarp system.

Resolving this complexity is challenging and, to do it, the researchers focused partly on seafloor morphology, in particular on the signs of seafloor rupture and instability, such as submarine landslides. Once the researchers started looking, they found the scarps had been affected by numerous landslides. The research team also found evidence of significant sediment transport, confined between salt domes and scarp walls. Sonar images showed signatures of high-energy events: ditches formed by erosion, indicating flow direction, plus perpendicular structures interpreted as pebble or gravel waves. These features probably constitute the sought-after signs of undersea earthquake activity, which can now be matched to other sites.

Direct sediment sampling compliments the scans. At the foot of the scarp slopes, the sediments are too mixed up to reveal any bedding that might be dated. Further out, this is not the case, and the presence of  turbidite beds alternating with another type of sedimentary deposit allows for some cautious dating of those layers. Preliminary results, from layers within the upper 1.5m of the core, show at least eleven turbidites accumulated during the Holocene, giving an average recurrence interval of about 800 years in this area. This matches the main seismic cycle on land, supporting the view that large earthquakes in Algeria are the main responsible for the large turbidity flows.

The authors concluded that the 2003 cable breaks were, for the most part, caused by the passage of a turbidity current triggered by the earthquake. The likely path of currents depends on the roughness and the irregularities of the sea floor: seafloor scarps in some cases deflect turbidity flow paths, while perched basins may trap them. The scarps seem prone to sediment failure, and are potential additional sources of cable breaks.

By Wayne Deeker, freelance science writer

On Friday, the EGU hosted a prolific Twitter discussion on the “Consequences of the L’Aquila verdict on the dialogue between science and society” where dozens of participants shared and discussed their thoughts on the verdict,  the scientific uncertainty surrounding earthquakes, and the outcomes of the decision for scientific research, communication, and education. You can now read the full transcript of the discussion on our Storify page.

If you didn’t get the chance to take part on the #eguAquila Twitter event, or would like to continue contributing to the discussion, you can do so on our blog forum.

Chris Rowan (@Allochthonous) summarises the L’Aquila issues in a tweet during Friday’s discussion

This Friday 26 October 2012 at 14:00 CEST we will host an online discussion about the consequences of the recent L’Aquila earthquake trial. Contribute by following the EGU’s Twitter account (@EuroGeosciences) and posting using the hashtag #eguAquila on your tweets. Please email the EGU’s Science Communications Fellow Edvard Glücksman if you have any further questions.

The earthquake in L’Aquila, Italy, killed 309 people and left 28,000 people homeless. (Photo: Boston.com)

Background

On Monday, an Italian judge sentenced seven members of Italy’s National Commission for the Forecast and Prevention of Major Risks, six scientists and a former government official, to six years in jail for manslaughter for providing “inexact, incomplete and contradictory” information to the public before an earthquake hit the town of L’Aquila, Italy, in 2009. Prosecutors in the case argue that 29 of the 309 deaths in the earthquake could have been avoided had people not been reassured by one of the experts that the situation was “normal” and that they should stay in the area. Critics argue that the role of science is not to make decisions about public welfare but, rather, to present information about hazards to decision-makers, who can then decide how best to proceed with mitigation strategies.

The EGU’s Division on Seismology has reacted to the verdict on their Division page with a statement that provides some insight on the possible consequences this case may have for the dialogue between science and society, and for scientific research itself.

How do you think this verdict will affect the science community? Will it affect you personally? If so, in what ways? And what effects will it have on the relationship between scientists, policy makers, and Europe’s legal system?

Speak your mind this Friday on Twitter!

You may find the following articles of interest for the discussion:

• Scientists on trial: At fault? (Nature, 15 September 2011)
• Seismologists found guilty of manslaughter (New Scientist, 22 October 2012)
• Conviction of Italian Scientists May Hinder Open Discussion of Seismic Risk (American Geophysical Union, 23 October 2012)
• Italian court ruling sends chill through science community (Reuters, 22 October 2012)
• Seismologists’ trial likened to persecution of Galileo (AFP, 23 October 2012)
• For more articles, check Google News.

Journalist Alexandra Witze was one of two winners of the EGU’s first Geosciences Communications Fellowship. We asked her to report back from a recent trip to Iceland, where she and her husband, science writer Jeff Kanipe, were gathering material on the 1783 eruption of the volcano Laki. They are working on a popular book about Laki for Profile Books.

Kanipe and Witze at Thingvellir National Park, along the Mid-Atlantic Rift. (Credit: Witze/Kanipe)

When you’re hot on the trail of a particular Icelandic eruption, it’s hard not to get distracted by all the other volcanoes that dot the landscape.

Just driving east from Reykjavik is like volcano overload. There, off to the left, is mighty Hekla, its snowy slopes rising dramatically. Up ahead is infamous Eyjafjallajökull, its shoulders still dusted with the dark ash that closed European airspace for a panicky week in spring 2010. And just behind that lies a massive ice cap smothering one of the island’s most active volcanoes: Katla.

It was this volcanological bounty that led the American Geophysical Union to hold a Chapman conference on volcanism and the atmosphere in the town of Selfoss in June. We attended all week, eager to learn about how Laki fit into Iceland’s violent past. On a field trip to Eyjafjallajökull, Thor Thordarson of the University of Edinburgh told the group how the eruption sent a glacial flood, or jökulhlaup, bursting from beneath the mountain’s ice cap to carve a devastating path to the sea. On another trip to Thingvellir National Park, we watched as workers repaired the visitor’s pathway that had been destroyed by the North American and Eurasian tectonic plates pulling apart — just another casualty of building right on the Mid-Atlantic Rift.

An outlet glacier on the north side of Eyjafjallajokull, taken during a conference field trip. (Credit: Witze/Kanipe)

We also learned how Laki’s 1783 outburst fit into the history of other climate-altering eruptions. For eight months the ground literally ripped open, sending fire fountains spurting along a fissure that eventually stretched for 27 kilometers. It was one of the biggest lava flows in historical times, and it pumped some 100 million tons of sulfur dioxide into the polar jet stream above Iceland. Those acidic fumes soon spread across Europe, killing crops and choking people.Particles spewed by Laki also reflected more sunlight back into space, cooling much of the Northern Hemisphere. Shivering in Paris in the winter of 1784, Benjamin Franklin and others proposed that an Icelandic eruption was to blame — the first scientific recognition that a volcano could cool climate. At an impromptu session on Laki convened the last day of the Chapman conference, Stephen Self of the Open University and others talked about how future computer modeling could resolve questions over how much of Laki’s aerosols made it to the stratosphere, and how many weird weather events in 1783–1784 can be blamed on it.

Within Iceland, the effects were obvious. Poisonous fumes including fluorine settled on the grass, killing livestock in a national disaster known as the “mist hardships.” One-fifth of all Icelanders died in the barren aftermath, many from starvation.

Two and a half hours east of Selfoss, the town of Kirkjubæjarklaustur was ground zero for this misery. Here a local priest named Jón Steingrímsson kept a grim census, recording the deaths of his parishioners one by one. Today his chronicle, known as the Eldrit or Fires of the Earth, is the main source of detailed information on the Laki eruption.

Just above the town of Kirkjubaejarklaustur, this pile of congealed lava in the middle of the Skafta river gorge shows where the lava flow stopped as Jon Steingrimsson led his famous fire mass. (Credit: Witze/Kanipe)

Steingrímsson was also a proto-volcanologist, and he carefully observed how layers of ash settled over the landscape and how lava traveled down the gorge of the Skafta river. Six weeks after the eruption began, when it looked as if flowing rivers of fiery rock would envelop the village, Steingrímsson famously led his spiritual flock into the church and prayed for deliverance. When they emerged they saw that the lava had miraculously stopped, just upstream from the village.

Or so the story goes. In reality, many of the experts we met say, Steingrímsson had been paying close attention to the lava, and he recognized that it would likely halt at the place where there was enough water to cool the flow and halt its advance. It was perhaps the earliest and most brilliant public-relations move by a budding volcanologist.

The ruins of the old church at Kirkjubaejarklaustur (buried beneath this lawn) are marked by a white cross to commemorate the famous fire mass, and a low horizontal gravestone marks the burial place of the priest Jon Steingrimsson and his wife. In the background of the picture, towards the left, is a low rise that marks a mass grave of victims from the 1783 Laki eruption. (Credit: Witze/Kanipe)

Thanks to the help of the EGU fellowship, we were able to visit the row of Laki craters and the village of Kirkjubæjarklaustur, where we stayed directly across the street from the ruins of Steingrímsson’s church. A simple white cross in the courtyard still commemorates the famous fire mass. Steingrímsson himself is buried at the site along with his wife, who died in the mist hardships. In one corner of the churchyard lie yet more victims of Laki, piled by the dozens in a mass grave. Most tourists driving through this town stop briefly to fuel their cars and get a bite to eat, unaware that modern volcanology took some of its first tentative steps here.

The row of Laki craters, seen stretching off into the distance. (Credit: Witze/Kanipe)

Other experts graciously shared their knowledge of Laki with us. Two hours north of Reykjavik, the volcanologist Haraldur Sigurdsson showed us around his excellent volcano museum and told us how glass inclusions in Laki rocks preserve chemical evidence of its high sulfur content. At the University of Iceland, historian Sveinbjörn Rafnsson walked us through how poor rural farmers would have coped with devastating 18th-century eruptions.

We returned home from Iceland with a bulging notebook, more than 1,000 photographs, and as many Laki souvenirs as we could find. Now our task is to tell the story of this amazing eruption.

By Alexandra Witze

After a couple of months of absence, GeoLog is once again hosting the Geosciences column. This month we have no less than two posts highlighting recent research in the Earth sciences. In the second of this month’s columns, Eline Vanuytrecht writes about recent research on flood risk published in the EGU journal Natural Hazards and Earth System Sciences.

If you’d like to contribute to GeoLog, please contact EGU’s Media and Commmunications Officer, Bárbara T. Ferreira at media@egu.eu.

Floods can cause serious damage in residential areas. Recent records show that the damage has increased over the last decades, placing floods as one of the most severe natural hazards. But what exactly was the main cause for this increase in damage? And how will the relative contribution of drivers of flood-risk change such as meteorological phenomena, land use and socio-economic developments evolve in the future?

Heavy precipitation, flood and measurements, by Bibiana Groppelli. Distributed by EGU under a Creative Commons licence

To answer these questions, a group of German researchers, led by Florian Elmer of the GFZ Research Centre for Geosciences in Potsdam, analyzed what drives changes in flood risk in the lower part of the Mulde River basin in Eastern Germany. They concluded, rather surprisingly, that land-use changes, not meteorological phenomena, are the main drivers of flood risk change.

“Consequently, the potential influence of local and regional land-use policies is substantial and could contribute significantly to (…) risk mitigation,” the authors write in the Natural Hazards and Earth System Sciences paper.

The study focused on the lower Mulde River catchment  but it can serve as bench-mark for complete risk analysis for other river systems. Flooding is common in this catchment, which comprises several municipalities and an area of approximately 1000km² of which around 8% is inhabited.

The scientists surveyed the change of flood risk in terms of expected annual damage in residential areas between 1990 and 2020 in 10-year time steps. The analysis was based both on observations (for the past period) and model projections (for future times). They further quantified how the cost and impact of floods are modified by each of these drivers: climate change, land-use change and changes in building values.

The results of the study show that, under changing meteorological conditions, including altering rainfall patterns and rising temperatures, only few changes in return time of floods of different magnitude are experienced. The return time of a flood is a measure for its frequency, which reflects the estimated average time between two events.

Predicted increases in flood risk are thus mainly related to land-use changes including paving of previously permeable surfaces. Since 1990, the region has undergone major socio-economic changes after the reunification of Germany, including population decrease. However, at the same time, the area saw urban sprawl and residential structure change towards single-family dwellings. This expansion of urban areas increases the area covered by impermeable pavements, hence increasing flood risk. The scientists expect to see more urbanization, and thus increased risk, in the future.

Interestingly, the monetary value of the estimated annual flood damage decreased from 1990 to 2000. This is due to a combination of factors after Germany’s reunification leading to an exceptional situation of high inflation after 1990. In the future, however, the authors predict increasing damage values.

Another interesting conclusion is that small to moderate flood events dominate the risk expectation. These events combine relatively small flood volumes with a high return time (less than 20 years).

The results of the research hold an important message for flood-risk policy. Since land-use change is identified as the main driver of flood-damage change, a key role is reserved for land-use policies in risk mitigation. Further, since the majority of the annually expected damage can be attributed to small to moderate floods occurring frequently, relatively easy-to-install protection measures can erase substantial part of the damage.

By Eline Vanuytrecht, freelance writer & PhD student, KU Leuven

The EGU is responsible for 14 Open Access journals, all freely available online

Since 2001, the EGU and Open Access publishing house Copernicus Publications has published a growing number of successful geoscientific journals. These include 14 peer-reviewed Open Access journals, of which 11 have a Thomson Reuters Impact Factor, placing them in the top echelon of their respective discipline. EGU also publishes a host of other materials available in paper and online. As a signatory of the Berlin Open Access Declaration (2003), the EGU is committed to making all their publications freely available.

The EGU’s Open Access scientific journals are:

• Annales Geophysicae (ANGEO), Impact Factor 1.62
• Atmospheric Chemistry and Physics (ACP) & Discussions (ACPD), IF 5.309
• Atmospheric Measurement Techniques (AMT) & Discussions (AMTD), IF 2.623
• Biogeosciences (BG) & Discussions (BGD), IF 3.587
• Climate of the Past (CP) & Discussions (CPD), IF 2.821
• Earth System Dynamics (ESD) & Discussions (ESDD)
• Geoscientific Instrumentation, Methods and Data Systems (GI) & Discussions (GID)
• Geoscientific Model Development (GMD) & Discussions (GMDD), IF 1.591
• Hydrology and Earth System Sciences (HESS) & Discussions (HESSD), IF 2.463
• Natural Hazards and Earth System Sciences (NHESS), IF 1.792
• Nonlinear Processes in Geophysics (NPG), IF 1.300
• Ocean Science (OS) & Discussions (OSD), IF 1.443
• Solid Earth (SE) & Discussions (SED)
• The Cryosphere (TC) & Discussions (TCD), IF 3.641

This blogpost is a round-up of potentially useful weblinks to information about the earthquake off the west coast of northern Sumatra of 11 April 2012. The links provided here are external and do not reflect the opinions of the European Geosciences Union.

Real-time seismic monitor (source: IRIS)

Regarding the earthquake, the US Geological Survey’s  (USGS) Earthquake Harzard Program homepage features seismic activity maps and a summary of the event. The USGS also has a map and list of earthquakes in the Asia region, showing aftershocks in real time on a map.

Concerning the tsunami, the Pacific Tsunami Warning Center, run by the National Oceanic & Atmospheric Administration, has its own pages and a specific one on today’s activity.

The Global Disaster Alert and Coordination System also has various models related to the earthquake and tsunami.

Finally, the IRIS Seismic Monitor has lots of resources designed for teaching, including a Powerpoint presentation and animations. The Harvard Seismology page also contains research and animations.

Thank you to Charlotte Krawczyk, president of the EGU seismology division, for providing these links.