Ingmar Unkel

Prof. Dr. Ingmar Unkel

As the fourth coring expedition in March 2018 , we were delighted to welcome Dr. Ingmar Unkel as a new member to our team in Biển Hồ maar lake. We expect even better and deeper cores from the campaign, especially with Ingmar’s advice.

Ingmar is a hydrogeologist by Diploma (Master) and have quite some experience with karst environments in Greece and in Austria.  Since Ingmar’s PhD, he shifted more and more towards palaeoclimate reconstructions using now mainly lake sediments, geochemical proxies, and radiocarbon dating. Ingmar expertise in radiocarbon dating and modelling confines the time range of interest to the last 50,000 years.

After practicing 8 years of Vietnamese version of fighting (Việt Võ Đạo) it is a dream of Ingmar or many years to one day visit Vietnam.

The Maar Lake region in Central Vietnam is quite interesting, especially as maars often have the potential for laminated sediments. And Central Vietnam is in an excellent position to investigate shifts of the monsoon belt over glacial/interglacial periods. Ingmar interests doing future research in Vietnam.

Ingmar is a very careful world expert in XRF data interpretation and statistics. He is working with the open source software R for plotting and analysis of data. Ingmar supports the EOS group to apply R and do the respective analyses. With a longer perspective, he can offer us to give an R course at VNU during his future visit to Vietnam to train our group and students in R.

Below are a few pictures highlighting Ingmar’s activities in Vietnam in March 2018.

Biển Hồ maar lake viewed from airplane, March 18, 2018.
Dương, Ingmar and Hướng at a lookout tower at the end of the peninsula in Biển Hồ lake, March 2018.
Team members visit an assembly point near the shore to Biển Hồ maar lake , March 2018. This time the lake water level is about 1.5 m lower than November 2017.
Team members at our platform before rowing to coring sites on Biển Hồ lake, March 2018.
Ingmar at the platform before coring at a coring site on Biển Hồ lake, March 2018.
Ingmar and Dương with our piston corer, March 2018.
Team member trekking into a dry maar next to Biển Hồ lake, March 2018.
Team member posing into a dry maar next to Biển Hồ lake, March 2018.
Ingmar and Dương collects rock samples along the shore of Biển Hồ maar lake, March 2018.
Ingmar poses after finding his missing sun glasses in Biển Hồ lake, March 2018.
Ingmar rows the boat to coring sites on Biển Hồ lake, March 2018.
Team members celebrates for doing the very first freeze-coring ever in Biển Hồ, March 2018.
After a coring day team members rows the boats back to the shore of Biển Hồ lake, March 2018.
Team members have dinner at our favorite restaurant (Thành Tâm) not for from the lake, March 2018.
Biển Hồ maar lake from the south, March 2018.
Ingmar finally had the chance to take a hike around the entire lake! He collected 4 soil samples around the lake, using only his gloves, no metal and stored them in new zip-lock bags.
Ingmar also took the GPS coordinates and photos from the sampling sites. All samples were taken on the inner slopes of Bien Ho Maar at soil outcrops (vertical soil sections, not sampling the organic top soil).
From Biển Hồ maar lake we retrieved 18 sediment cores from up to 19 m water depth with up to more than 5 meter penetration into sediment. All cores were transported to EOS lab in Hanoi by airplane.

In March 2020 (just before Covid-19 made international travel all but impossible), our coring team including Ingmar retrieved an 8.7 m long sediment core from Ea Tyn Lake. The maximum coring depth was limited by the penetration capabilities of the available equipment and not by the solid-rock basement of the lake basin, which has not been reached yet.

Ingmar and the EOS team at the VNU campus in Hanoi (March 2020)
A drone image of the coring team including Ingmar in Ea Tyn lake, Dak Lak province (March, 2020)
A drone image of the coring team including Ingmar in Ea Tyn lake, Dak Lak province (March, 2020)

Twelve 14C AMS dates on single plant macrofossils and a 137Cs fallout profile indicate an extremely high sedimentation rate in the Ea Tyn Lake. Geochemistry, sedimentology, mineral magnetics, color properties, and macro-fossils of the Ea Tyn Lake record are currently being analysed by Ingmar, the EOS team and our international partners.

Sediment coring in Ea Tyn Lake (March 2020)
Preparation of sediment traps before mooring in Ea Tyn Lake (March 2020)
Campsite for the coring team during coring expedition in Ea Tyn Lake (March 2020)

Related publications

Ojala A.E.K., Nguyễn-Văn H., Unkel I., Nguyễn-Thùy D., Nguyễn-Đình T., Đỗ-Trọng Q., Sun C., Sauer P.E., Schimmelmann A., 2023. High-resolution ~55 ka paleomagnetic record of Biển Hồ maar lake sediment from Vietnam in relation to detailed 14C and 137Cs geochronologies. Quat. Geochronol. 76, 101443,

Nguyễn-Văn, H., Unkel, I., Nguyễn-Thùy, D., Nguyễn-Đình, T., Đỗ, T.Q., Đặng, X.T., Nguyễn, T.H., Đinh, X.T., Nguyễn, T. A.N., Nguyễn, H.Q., Đào, T.H., Nguyễn, T.H.T., Phạm, L.T.N., Lê, N.A., Vũ, V.H., Ojala, A.E.K, Schimmelmann, A., Sauer, P., 2023. Paleoenvironmental potential of lacustrine sediments in the Central Highlands of Vietnam: a review on the state of research. Vietnam Journal of Earth Sciences.

Nguyễn-Đình, T., Nguyễn-Thùy, D., Nguyễn-Văn, H., Ojala, A.E.K., Đỗ-Trọng, Q., Phan-Thanh, T., Nguyễn Thị, H., Nguyễn, T.A.N., Đinh, X.T., Nguyễn, T.H.T., Sauer, P.E., Schimmelmann, A., Unkel, I., 2022. High-resolution, 1250-year long drought record from Ea Tyn Lake, Central Highlands of Vietnam. The Holocene, 32, 10, 1026–1040.

Nguyễn-Văn, H., Schimmelmann, J.P., Nguyễn-Thùy D., Ojala, A.E.K, Unkel, I., Nguyễn-Đình, T., Fukumoto, Y., Doiron, K.E, Sauer, P.E., Drobniak, A., Nguyễn-Thùy, D, Nguyễn, T.A.N, Đỗ-Trọng, Q., Nguyễn-Thị, H., Nguyễn-Ánh, D., Nguyễn-Văn, T., and Schimmelmann, A., 2022. Environmental history recorded over the last 70 years in Biển Hồ Maar sediment, Central Highlands of Vietnam. Quaternary International, 621, 84-100.

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