GaiaCode's unique multidisciplinary geophysical borehole observatory in Türkiye is now fully operational. A continuous stream of digital data from more than 15 geophysical sensors plus the measurements of an uphole weather station are transmitted in real-time to a data center jointly operated by the Turkish Disaster and Emergency Management Presidency (AFAD) and the German Geoscience Research Center (GFZ).
A Major Augmentation to GONAF
The new data streams are a major augmentation of the GONAF research initiative by both agencies. The acronym GONAF stands for “Geophysical Observatory at the North Anatolian Fault”. Its main objective is to measure tectonic deformation transients (seismic and aseismic) along the Marmara section of the North Anatolian Fault in northwestern Türkiye. This section is overdue for a major earthquake.
The 30 minute long waveforms above show a Mw=6.2 earthquake North of the Greek island of Crete on May 22, 2025 as recorded by some of sensors of the GONAF-2 borehole observatory. The top three traces (green, red and blue) are the three components (Z,N and E) of the ALPHA ultrabroadband borehole sensor. The fourth and fifth traces (blue and green) show the measurements of two tensor strainmeters while the last trace (yellow) shows the data from the bulk dilatometer. All the sensors were developed in-house by GaiaCode.
The new borehole observatory consists of two 110 meter deep boreholes immediately next to each other. One contains a three component ultra broadband seismometer of GaiaCode's ALPHA family, and at the bottom of the borehole a highly sensitive dilatometer measuring the bulk strain, a three component tensor strainmeter based on the output of capacitive transducers and an arrangement of six 4.5 Hz geophones. A pore pressure meter is cemented into the bottom of the second borehole.
The three component strainmeter of the multidisciplinary geophysical borehole observatory
The current unique multidisciplinary borehole station is installed on the northern tip of the Kapidağ Peninsula on the southern coast of the Marmara Sea. Two more borehole stations with the same sensor arrangement are planned for locations along the North Anatolian Fault on the northwestern shore of the Marmara Sea.
