Publications Published/ in Review/ Submitted/ in Preparation

Pdfs available e.g. via email (see contact details):

Monitoring the Vent Activity and Growing Lava Flow Field with Eruptive Tremor

Our latest article is entitled: “Multiple Coincident Eruptive Seismic Tremor Sources During the 2014-2015 Eruption at Holuhraun, Iceland” and describes the eruptive tremor that was generated during the largest effusive eruption in the last 200 years.

We analyzed a type of earthquake that is long lasting, has no sudden start but is slowly getting stronger, and is recorded during eruptions. This so-called tremor is usually thought to be merely caused below the vent where the magma moves up toward the surface. Therefore, it was, for example, used to estimate how much magma and how fast the magma erupts, how high, and where the erupted magma would go. However, using a dense network of seismometers at only 15 km distance from the erupting magma – during the Holuhraun eruption in Iceland in 2014/2015 – we found three areas where tremor is caused. These are (i) below the vent where the magma moves up toward the surface, (ii) at the cooling sides of the growing lava flow field, and (iii) probably at less than 2 km depth where the Earth’s crust breaks and magma moves horizontally. We warn other scientists to be careful when using the tremor amplitude but also show that we can with our instruments watch in real time where the lava flow field is growing.

link to the paper   or pdf available via email (see contact details)

Locating and tracking a helicopter with 7 seismometers

Following our first publication in 2015 about tremor generated by helicopters, we developed and now describe a method how we can locate and track it.The method is described in our article: “Helicopter location and tracking using seismometer recordings

We use the recordings of the ground movements of 7 seismometers excited when the helicopter passed our stations at more than 200 m height. Passing our stations, the helicopter generated a frequency downgliding due to the Doppler Effect. The shape of this downgliding at each station depends on (i) the speed of the helicopter, (ii) the speed of rotation and number of its blades and (iii) the distance to the station.

Based on the shape of the Doppler glides we can with our location method determine not only the (i) the speed of the helicopter, (ii) the speed of rotation and number of its blades, but also (iii) the flight direction, (iv) the flight height and (v) lateral location of the helicopter with respect to our stations (location in x & y).

link to the paper  or pdf available via email (see contact details)

New insights into how continuous seismic signals announce an eruption

Our new article “Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland” describes a new understanding of seismic signals prior to an eruption. The focus of the study is the eruption at Holuhraun in Iceland in 2014/15 that was preceded by two weeks of increased, 48 km migrating seismicity. This seismicity is the noise of the breaking crust at depth and gave scientists the possibility to watch how magma propagated horizontally until it eventually made it to the Earth’s surface. However, the puzzling observation was that no high-frequency earthquakes occurred at less than 3 km depth, although magma passed through this region. We found that a long-lasting continuous seismic signal, called tremor, exists at this depth instead and announces an eruption. This tremor is usually understood as being caused by moving fluids, but it seems that it consists instead of millions of tiny earthquakes that are so closely spaced that they merge into one another and appear as tremor. It seems that the uppermost part of the crust is too weak to generate big earthquakes and it therefore breaks through many small earthquakes and that magma flowed silently in the crack. In our paper we describe how the crust beneath the ice opened little by little in about 19 hours at a speed of 220 m/h. As such eruptions beneath ice can distribute huge amounts of ash in the air, understanding these signals is important for volcano monitoring and eruption early-warning.

link to the paper    pdf also available via email (see contact details).

The Earth’s crust opens in steps above flowing magma at depth

During many of the world’s largest volcanic eruptions large cracks open at the Earth’s surface while magma is flowing horizontally at depth. Our paper “Micrometre-scale deformation observations reveal fundamental controls on geological rifting” describes how the crust cracks in details, which is in general poorly understood. The recordings of lower resolution GPS instruments for example just show a crack opening at constant speed.

We analysed the much higher-resolution recording of a seismometer during the 2014-2015 eruption at Holuhraun in Iceland. This instrument was put directly above the flowing magma at depth. Its recordings show on a very detailed scale (less than one second in time and micrometre in space) that the crust opens in many steps during repeated low magnitude (MW < 0) earthquakes on fracture patches estimated between 300 m2 and 1200 m2 in size. We found that the uppermost crust in the opening area is very weak.

link to the paper

Funding

  • 4/2017:                     Marie Sklodowska-Curie Actions Seal of Excellence for not funded Marie Curie Individual Fellowship proposal submitted in 9/2016
  • 9/2016: Award of “General Fall Meeting Student Travel Grant” of AGU ($1000) to attend AGU 2016
  • 3/2016: Eva secured SEED Funding from UCD to attend EGU 2016 (€ 1380)
  • 2/2016: IPGP Foreign Student Award 2016 (worth ~€ 800)
    − Fellowship to visit IPGP in March 2016
    − Oral presentation at Congrès des Doctorants
    − 9 awardees out of 80 applicants
  • 4/2011 – 8/2012: Award of “Deutschlandstipendium”  (€ 300/month)
    − Government stipend based on academic merit and leadership promise
    − Awarded to 0.5% of German university students
  • 7/2008: Award of € 800 Conference Grant (used for EGU attendence 2009) from Department of Earth and Environmental Sciences of LMU for the best field mapping in 2008 (1st of 13)
  • 3.5 years of her PhD was funded through FutureVolc (Funding was received from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No 308377.)

Awards

  • 3/2013: Best Poster Award IRGM 2013 (1st of 35): € 250
  • 10/2011 – 10/2012: Admission to Mentoring Programme of LMU for Postgrads as an Undergrad
    − LMU intern programme based on academic merit and leadership promise
    − Admission of Undergraduates only in exceptional cases
    − Personal and financial support
    − Acquisition of soft skills in various seminars
  • 4/2011: Refund of Tuition Fee Paid During B. Sc. Studies: € 2800
    – Finished as one of the best 10%
    – Finished within the designated period of study