Late Quaternary High-Resolution Climate Archives in the Sahara

Exploring the subsurface – Geophysics in the Azraq Basin, Northern Jordan

Non-invasive surface geophysical techniques are a useful tool to investigate the earth’s subsurface structure. In order to identify suitable locations for future drilling projects, the Qa Al’ Azraq mudflat in northern Jordan was investigated in March 2011 using three surface geophysical methods. Our investigations made use of the Transient Electromagnetic (TEM), the Direct Current Resistivity (DCR) and the Radiomagnetotelluric (RMT) methods.

A 5 km long subsurface resistivity model was derived from the geophysical data. The 1D TEM models are stitched together and presented as a 2D subsurface electrical resistivity section.

Previously, diffuse lithological boundaries were clearly detected. In particular, the precise depth to the basalt stream was identified along the section. From 0 to 3000 m along the section line the topsurface zone coincides with a clay layer intermixed with limestone, chert, gravel and plant roots. On top of the basalt stream, a quite thin soft clay layer can be observed.

The resistivity models derived by 1D/2D inversion of geophysical data are compared and calibrated with lithological data from boreholes available along the section.

 

 

b1_yogeshwar_fig1_400px
1D TEM models stitched together as a 2D section for the 5 km long profile.
Illustration: Pritam Yogeshwar

ProjectProject

Project

Project A2
completed in 2017
(1st Phase) + (2nd Phase)

 

Principal Investigator:

Dr. Stefan Kröpelin
Prof. Dr. Bülent Tezkan
Prof. Dr. Martin Melles

 

Researcher:

Pritam Yogeshwar

 

PhD Candidate:

Jan Kuper
Marc Seidel

Raising the Sahara’s most complete climate record

Raising the Sahara’s most complete climate record

Coring the complete set of deposits at the bottom of a desert lake in northeast Chad in one of the driest and most isolated parts...

Exploring the subsurface – Geophysics in the Azraq...

Exploring the subsurface – Geophysics in the Azraq Basin, Northern Jordan

Non-invasive surface geophysical techniques are a useful tool to investigate the earth’s subsurface structure. In order to identif...

Advances in laboratory analyses of the Lake Yoa lo...

Advances in laboratory analyses of the Lake Yoa long core

While planned field work in Wadi Shati in Libya was impossible for obvious reasons, progress has been made on laboratory analyses...

Resolving sedimentary deposits in the Azraq Basin/...

Resolving sedimentary deposits in the Azraq Basin/Jordan using non-invasive geophysical techniques

A second geophysical field survey was undertaken in the Azraq Basin in October 2012.  

The lakes of Ounianga – Chad's first UNESCO World...

The lakes of Ounianga – Chad's first UNESCO World Heritage site

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Into the Sahara Desert’s Deep Past. Expedition to...

Into the Sahara Desert’s Deep Past. Expedition to the Remote Tibesti Mountains

It is hard to believe: We have sent a probe 500 million km to a comet to analyze rock samples, but no geologist has yet dug his sp...

Applied Geophysics at Lake Chew Bahir, Southern Et...

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In November/December 2014, four scientists from the Institute of Geophysics and Meteorology of the University of Cologne conducted...

Exploring sedimentary basins in the East-African R...

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Three month after the first journey to Southern Ethiopia, a group of scientists from the Institute of Geophysics and Meteorology o...

Ennedi mission

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The paradox of the Tibesti crater palaeolakes (Sah...

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Back from another mission in the Tibesti (Central...

Back from another mission in the Tibesti (Central Sahara)

A2 members just returned from another equally demanding as rewarding four-week expedition in the Tibesti mountains. The team compr...

The Ennedi Massif: Natural and cultural landscape...

The Ennedi Massif: Natural and cultural landscape – Chad’s second World Heritage site

18 years after an initiative taken by Stefan Kröpelin in 1999, UNESCO’s World Heritage Committee has unanimously inscribed the Enn...

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