NH
Natural Hazards

# Natural Hazards

## How to study Mega-earthquakes? By generating them!

Dr. Francesca Funiciello

Francesca Funiciello is an Associated Professor at Roma Tre University (Rome, Italy). Her research interests are, among others, geodynamics, seismotectonics, rheology of analogue materials and science communication. She leads an active and young research group composed by Fabio Corbi, Silvia Brizzi and Elenora van Rijsingen, and collaborates with many other young and experienced researchers in Europe. The main activities of Francesca, Fabio, Silvia and Elenora involve analogue and numerical modelling of subduction zones, geophysical data analysis and geostatistics in the field of mega-earthquakes.

1. Hi guys, can you tell us a bit more about “mega-earthquakes” and why it is so important to study them?

The interface between the subducting and overriding plates (Fig.1), the so-called megathrust, hosts the largest earthquakes on our planet Earth. They are generally called mega-earthquakes, with the prefix ‘mega’ highlighting both the fault originating them and their size. A quite recent example of a mega-earthquake is the Sumatra-Andaman event that occurred in 2004. The length of the fault that ruptured was ca. 1000 km and it generated a magnitude in the range of Mw 9.1–9.3 (Lay et al., 2005; Stein & Okal 2005; Subarya et al., 2006; Fujii & Satake 2007), where Mw denotes moment magnitude, a logarithmic measure of earthquake size. There had not been an event so large since the 1964 Alaska earthquake. The energy released during the Sumatra-Andaman 2004 event was in the range 5–10×1022 Nm—equivalent to the sum of the moment of all earthquakes in the preceding decade, worldwide (Lay et al., 2005).

Figure 1 – Schematic section through a subduction zone. The interface between the overriding and subducting plate is the so-called megathrust. The red star highlights the hypocenter of a megathrust earthquake (courtesy of S. Brizzi).

Subduction mega-earthquakes (together with the tsunamis they may generate) are among the largest hazards for human life, considering that millions of people live in proximity of subduction zones (e.g., the NE-Japanese and South American subduction zones), which are located at the edges of the Pacific Ocean.

1. Which approach does the scientific community adopt to study mega-earthquakes?

## The emergency of disaster emergency planning

Today I have the honour to introduce Prof. David Alexander as our guest. David is Professor of Risk and Disaster     Reduction at University College London (UK). His expertise comprises holistic aspects of disaster risk reduction and practical matters in emergency planning and management. He has also worked as Scientific Director of the Advanced School of Civil Protection of the regional government of Lombardy (Italy). As a Professor at the University of Florence (2005-11) he was a leading member of the team that designed, launched and taught Italy’s first Master of Civil Protection course.

David Alexander is the founder and Editor-in-Chief of Elsevier’s International Journal of Disaster Risk Reduction and was formerly Co-Editor of Disasters journal. He is Vice-President and Chairman of the Trustees of the Institute of Civil Protection and Emergency Management, which is the oldest learned society in the field of disaster reduction. He strongly supports the idea that “we are part of the civil-protection process. […] Therefore, we should all prepare for the next disaster as remarkably few of us will be able entirely to avoid it”.

1. How can we define ‘disaster emergency’?

Not all emergencies are disasters. Two books have been written on the topic of ‘What is a disaster?’, which shows that the definition is open to many different interpretations. An emergency can be defined as a situation caused by a threat or hazard that cannot be managed with ordinary, workaday procedures and resources. It requires rapid response via a qualitative change in the way things are done. Most emergencies involve actual or potential (i.e. imminent) damage and destruction, or at least serious disruption, and possibly casualties.

## Volcanic tourism, in between fascination and hazard awareness. Episode 1: the volcanologist prospective.

This picture captures the Lascar volcano, part of the Central Volcanic Zone of the Andes. It is the most active volcano of the region. Image credit: Joselyn Arriagada-Gonzalez (distributed via imaggeo.egu.eu)

Volcanoes are often located in stunning and fascinating places of the world. Some volcanoes are in areas already heavily populated, like Popocatépetl in Mexico or that thanks to tourism become highly or more populated during certain times of the year, like Agung in Indonesia.

In addition to the charm, volcanoes can be and have been harmful to both lives and properties. The hazards posed by volcanoes erupting are various and can affect areas both in the vicinity and far away from the eruption. Common hazards are, for example, lava flows, pyroclastic density currents, ash fall, ejection of ballistic, lahars, volcanic gases as well as structural collapses causing landslides, and eventually, tsunamis if close to the sea or a lake.

There will be some indications, some precursors, that a volcano is going to erupt. However, the time between these signs and the eruptive event is highly variable and can range from days to months. Sometimes an eruption can happen without a clear warning and be fatal, like the Mt. Ontake eruption in Japan in 2014.

Preparedness is thus crucial: be aware of where you are, the possible hazards and how to prevent or minimize losses and accidents. Scientists from all over the world have been more and more working closely with the communities at risks from volcanic activity. Advancements in volcano monitoring help better understand the phenomena. And educational programs and emergency simulations are commonly put in place. However, how are tourists taken into account in hazard mitigation plans? How aware are tourists of the natural hazards they may encounter? Are visitor centres providing enough information? What about tour operators?

To try and answers some of these questions we interviewed a scientist working on volcanic hazard and issues related to tourism. In today post, we welcome Bradley Scott from GNS Science, New Zealand.

## Fantastic grants and where to find them, part 1.

At some point in your career, usually, sooner than later, you will need to write a grant proposal to ensure yourself a paid research position.

Funding agencies are out there waiting to receive your great and original ideas and possibly grant you some money to transform these ideas into actual science. One can spend an entire day just researching on the internet the best funding scheme. To help in this quest, we start here a list of funding schemes for geoscientists at PhD and postdoc level available in Europe, but not limited to European applicants. For each scheme, we provide a short description and a link to where to find more information: just click underlined words.