GeoLog

drones

Imaggeo on Mondays: Salt shoreline of the Dead Sea

Imaggeo on Mondays: Salt shoreline of the Dead Sea

This beautiful aerial image (you’d be forgiven for thinking that it was a watercolour) of the Dead Sea was captured by a drone flying in 100m altitude over its eastern coastline.

Climate change is seeing temperatures rise in the Middle East, and the increased demand for water in the region (for irrigation) mean the areas on the banks of the lake are suffering a major water shortage. As a result, the lake is shrinking at an alarming rate. Currently, it is shrinking by over 1m/year. The image was captured as part of a survey in the wider project DESERVE (Kottmeier et al. 2016) addressing the environmental changes accompanying the lake level drop.

In this case, the special focus is to look for e.g. submarine springs or other geomorphological evidence in the shallow lake water that can later turn into hazardous sinkholes (cf. recent publication on that topic Al-Halbouni et. al. 2017). Learn more about the environmental challenges and geohazard risks the region faces in this December 2016 Imaggeo on Mondays post.

The round features see in this image, nevertheless have been identified as salt accumulations following basically the sinusoidal shoreline.

The different colours of the lake indicate water of varying densities, e.g. fresh water floating on top of saltier water and possible sediments inside.

The shoreline appears with different colours each year depending on the sediment mud & evaporite material. Each line represents the retreat of a given year!

[Editor’s note: this image was a finalsit in the 2017 Imaggeo Photo Contest]

By Laura Robert and Djamil Al-Halbouni of the German Research Center for Geosciences, Physics of the Earth, Potsdam, German

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/.

 

Imaggeo on Mondays: Lusi from the sky with drones

Lusi from the sky with drones. Credit: Giovanni Romeo, Adriano Mazzini and Giuseppe Di Stefano. (distributed via imaggeo.egu.eu)

Lusi from the sky with drones. Credit: Giovanni Romeo, Adriano Mazzini and Giuseppe Di Stefano. (distributed via imaggeo.egu.eu)

The picture shows a spectacular aerial view of a sunset over the Lusi mud eruption in East Java, Indonesia. Here thousands of cubic meters of mud, are spewed out every day from a 100 m sized central crater. Since the initial eruption of the volcano in 2006, following a 6.3 M earthquake, a surface of about 7 km2 has been covered by boiling mud, which has buried more than 12 villages and resulted in the displacement of 40,000 people.

Monitoring Lusi is part of multidisciplinary project called Lusi Lab, which focuses on the study of the behaviour of this incredible mud eruption. Many unsolved questions remain: What lies beneath Lusi? Research focuses on trying to ascertain what triggers the mud eruptions. One key question is whether Lusi is truly a mud volcano, or is it connected to a hydrothermal system linked to the nearby Arjuno Welirang volcanic complex? Lusi erupts mud, water, gas and clasts in pulses and scientists do not fully understand how the intermittent activity is linked to the seismic activity of the neighbouring volcanic complex. For the purposes of hazard and risk management, much speculation has focused on how long is the activity at Lusi is likely to last.

In an attempt to shed light on some of these questions the Lusi Lab team continually collect water and gas samples from the volcano, as well as assessing the seismic activity in the region ( including the neighbouring volcanic arc) through the deployment of a network of seismometers. This data gathering effort is further supported by a UAV prototype: The Lusi drone (assembled and equipped by INGV, Rome). The drone is able to access extreme environments and can provide photogrammetric and thermal images, gas and mud sampling and contact temperature measurements. A permanently installed Gopro Hero3 camera provides a continuous recording over the mud flows during flights, including this week’s Imaggeo on Mondays image.  Gas and water samples collected from the crater site revealed that Lusi is part of a Sedimentary Hosted Geothermal System (SHGT) that connects Lusi with the neighbouring Arjuno Welirang volcanic complex that can be seen in the background of the picture. The eruption site is continuously fed by new surges of geothermal fluids released from the volcano in particular after frequent seismic events occurring in the subduction zone in southern Java.

By Laura Roberts Artal and Giovanni Romeo 

To learn more about Lusi take a look at this paper:

Mazzini, A., Etiope, G., and Svensen, H. (2012), A new hydrothermal scenario for the 2006 Lusi eruption, Indonesia. Insights from gas geochemistry: Earth and Planetary Science Letters, 317-318. 0, 305-318.

If you pre-register for the 2015 General Assembly (Vienna, 12 – 17 April), you can take part in our annual photo competition! From 1 February up until 1 March, every participant pre-registered for the General Assembly can submit up three original photos and one moving image related to the Earth, planetary, and space sciences in competition for free registration to next year’s General Assembly!  These can include fantastic field photos, a stunning shot of your favourite thin section, what you’ve captured out on holiday or under the electron microscope – if it’s geoscientific, it fits the bill. Find out more about how to take part at http://imaggeo.egu.eu/photo-contest/information/.

Follow

Get every new post on this blog delivered to your Inbox.

Join other followers: