John Jansen



erosion | sediments | landscapes

I am a researcher and teacher based in Prague. Our group explores the dynamics of rivers and glaciers with the aim of understanding how climate, tectonics and life transform Earth's surface through time.





 Jordan Valley Palaeolithic
July 2024: Ten days fieldwork in the furnace heat of the Jordan Valley with Mahmoud Abbas (Jiaying University). Following our work on human occupation sites in Jordan dated to the last glacial cycle at wadis Gharandal, Gregra and Hasa, we are turning our attention to the earlier pre-Homo sapiens dispersals out of Africa. We collected samples to apply cosmo burial dating to two conglomerate units—the Abu Habil and Tabaqat formations—bearing stone artefacts of probable Early to Middle Pleistocene age. 

Wadi Abu Habil, the Abu Habil conglomerates & the Jordan Valley beyond.

Mahmoud at an exposure of tool-bearing fluvial gravels in Wadi al-Himar.

 6th Cosmo Workshop – Cologne
May 2024: Co-authoring the following presentations:
Jandová et al. (2024) Dating of moraines by cosmogenic nuclides
Knudsen et al. (2024) Redrawing early human dispersal patterns with cosmogenic nuclides
Ylä-Mella et al. (2024) Burial dating with P-PINI unveils the early Pleistocene glaciations
Jansen et al. (2024) Recent uplift of the Blue Mountains revealed by P-PINI burial dating.

Kölner Dom

 2024 EGU – Vienna
Apr 2024Five presentations from our research group this April in Vienna:
Guha et al. (2024) The first glaciers at Ivrea, southern Alpine Foreland
Ruetenik et al. (2024) Spatially variable sea level response to erosion and deposition in Aotearoa New Zealand
Wagner et al. (2024) Early Pleistocene onset of glacial incision in the Baltic Basin revealed by 10Be-26Al burial dating ...
Ylä-Mella et al. (2024) Unveiling the early Eurasian glaciations with new advances in 10Be-26Al burial dating.
Jansen et al. (2024) Redrawing early human dispersal patterns with cosmogenic nuclides. This work on human dispersal featured in an EGU press conferencethe GeoLog and an article in New Scientist.

 Back at the Chengdu landslides lab
Mar 2024: Visiting professor at the SKLGP for 6 weeks of Hotpot and landslides, working with Xuanmei Fan and her team on many new and fun projects, including deep-learning applied to landslide prediction, shaker-table experiments, and soft-sediment deformation structures. I also spent a couple of sunny days in the Longmenshan with Lanxin and Jingjuan.

Lanxin Dai & Jingjuan Li collecting cosmo samples at Diexi, Longmenshan, where
the 
Minjiang has cut 4 different fluvial epigenetic gorges.

Rock deformation, Institute of the Geological Survey, Chengdu University of Technology.

Frank's head

A big orange head.

 The first Europeans 1.4 Ma in western Ukraine
Mar 2024: We applied cosmo burial dating (P-PINI) to sediments containing stone tools excavated in Korolevo, western Ukraine. The burial ages turn out to be the earliest dated human presence in Europe. Our study, East-to-west human dispersal into Europe 1.4 million years ago, led by Roman Garba (Czech Academy of Sciences) is published in Nature. An accompanying essay: The First Europeans reached Ukraine 1.4 million years ago is published in The Conversation.  

Mode-1 'core-and-flake' stone tools excavated and dated at Korolevo: (A) chopper-core, (B) bifacial flake, (C) multiplatform core,
(D) Kombewa flake, (E) flake with parallel scars (image: Vitaly Usik).

Our burial ages at Korolevo suggest early human dispersal into Europe from east to west.

 ANZGG meeting in Tairāwhiti, Aotearoa New Zealand
Feb 2024: Attending the 20th meeting of the Australian & New Zealand Geomorphology Group (established 1982) together with the pre- & post-conference field trips around the North Island. My presentation: Jansen et al. (2024) Disequilibrium in Australia's continental interior was based on Greg's recent modelling work.

Catastrophic channel widening & aggradation on a tributary of the Waipu River in the wake of cyclone Gabrielle one year ago.

 
Out of Africa via the Jordan Valley
Oct 2023: Our new work led by Mahmoud Abbas focusing on three wetland sites in the Jordan Valley: Human dispersals out of Africa via the Levant is published this month in Science Advances, together with New path for early human migrations through a once-lush Arabia contradicts a single 'out of Africa' origin in The Conversation, and Water corridors helped Homo sapiens disperse out of Africa in EOS.

Mahmoud Abbas, Paul Carling & me sampling a section at Wadi Gharandal where a
stratified Levallois flake is constrained with OSL to 84 ± 5 ka (photo: LM Gibbs).

 Blue Mountains archaeology
Aug 2023: Some days walking in the Blue Mountains, west of Sydney, investigating rock shelters and open sites with my old friend, Marshall Wilkinson (formerly University of Kentucky).

Axe-grinding grooves on a rock outcrop.

Marsh at an unnamed rock shelter above Queen Victoria Ck.

 Tasmania's earliest Pleistocene glaciations
Aug 2023: A visit to the West Coast Range to apply cosmo burial dating to sediments laid down during the Bulgobac and Linda glaciations—possibly the two oldest glaciations in Tasmania. Previous workers, Eric Colhoun and Paul Augustinus, report reversed geomagnetic polarity, placing both glaciations in the Early Pleistocene (>0.8 Ma). After receiving some helpful advice from Paul, I collected samples from the Bulgobac glacial till in the upper Pieman basin, and the Linda glacial till from the Linda valley at Gormanston. Together with the Ross and Porika glacial tills sampled in Aotearoa NZ last year, these western Tasmanian samples will build a picture of when ice sheets first started building at mid-latitudes in the southern hemisphere.

Strongly weathered, steeply-dipping glaciolacustrine sediments in the Linda valley.

The King valley hosted major outlet glaciers during the early Pleistocene glaciations.

 
INQUA meeting in Rome
July 2023: Co-authoring the following presentations:
  • Broś et al. Age of the oldest sediments in the northern Swiss Alpine foreland.
  • Carling et al. Ice buttressing-controlled rock slope failure on a cirque headwall, English Lake District.
  • Garba et al. The first hominins of Central Europe ... at Korolevo I, western Ukraine.
  • Szuman-Kalita et al. Southern margin of the Scandinavian Ice Sheet in northwest Poland during the last glacial cycle.
  • Wagner et al. Establishing the timing of the first Fennoscandian ice sheet advances in the North European Plain.
  • Ylä-Mella et al. A new dating advance in archaeology: cosmogenic burial dating with P-PINI at Korolevo I.

 The seismological observatory at Kašperské Hory
Jun 2023: A few restful days at the newly renovated GFÚ facility in the Šumava Mountains of southern Bohemia: Kašperské Hory Observatory


 2023 EGU – Vienna
Apr 2023: A return to Vienna after a 4-year break with Nørgaard et al. (2023) East Siberian glaciers have contracted over the last two glacial cycles. This work is now published in Geophysical Research Letters.

Kleines Café

 Czech Science Foundation funding to Greg Ruetenik
Dec 2022: Celebrating the funding of our 3-yr project led by SPP researcher, Greg Ruetenik: Interplay between relative sea-level & surface processes: comparing responses across tectonically active & inactive terrains

Sea-level rise is known to be a potentially catastrophic outcome of global climate change, but measuring sea-level change is complicated by Earth's surface vertical motions, the redistribution of rock and sediment, and variations in the gravitational field. In this project, we will simulate the evolution of topography with a landscape evolution model that includes sea-level change using data from tectonically inactive vs active continental margins. We will then drive a global, gravitationally self-consistent sea-level model with our erosion/deposition estimates to determine their influence on sea level over multiple glacial cycles. Our aim is to provide a better understanding of sea-level and corresponding topographic responses in diverse global settings.


 Oldest glacial sediments in Aotearoa New Zealand 
Sept 2022: Fieldwork with Kevin Norton and Brian Anderson (Wellington) sampling glacial till from the type localities of the Ross and Porika glaciations, which are thought to represent the oldest and second-oldest large-scale glaciations in Aotearoa New Zealand—current estimates are ~2.5 Ma and ~2.2 Ma, respectively. We aim to apply cosmo burial dating to resolve the age of these ancient glaciations.

Ross and Porika type localities, South Island. 


Ross till — a mix of angular and rounded clasts with extremely weathered granites.

In the Travers Range.

 'First ice sheets' field season completed for 2022 
Sept 2022: PhD candidates, Lotta Ylä-Mella and Kaleb Wagner, and other team members this summer collected ~200 samples of glacial sediment at 19 field sites (in Denmark, the Netherlands, Germany, Poland, and Lithuania) as part of projects funded by the Czech Science foundation. The next step is to prepare these samples for cosmogenic nuclide analysis at the Aarhus cosmo lab.


From top-left: (1) Lotta at the Gyldendal cliff exposure in N Jutland, Denmark. (2) Discussions at Starkenberg
gravel pit, E Germany (John Jansen, Kaleb Wagner, Stefan Wansa, Henrik Rother, and Shantamoy Guha).
(3) Kaleb and Albertas Bitinas sampling in Lithuania. (4) Sampling archived sediment cores at the Lithuanian
Geological Survey (Vaida Šerienė, Albertas Bitinas, and Lotta). (5) Examining the composition of till in SE
Poland (Izabella Szuman-Kalita and Jan Dzierżek). (6) Surveying tills at Liether Kalkgrube, NW Germany.

 Dating the first glaciers in the southern Alpine Foreland 
Aug 2022: The Ivrea moraines in Piemonte, Italy, are among the oldest glacial tills preserved in the southern foreland of the Alps and are thought to date back to the Early Pleistocene. We spent a week sampling the four oldest tills: Mongrando, Bornasco, Montino, and Zubiena, plus two underlying preglacial fluvial units: Muzzano and Cerrione. In this project, led by Shantamoy Guha (GFÚ), our goal is to apply the cosmogenic nuclide burial-dating model, P-PINI, to resolve the timing of the first major glaciations in the western Alps.

The Ivrea Moraine Complex—an impressive set of concentric moraine ridges (25 km across) dating back to the Early Pleistocene. These
ridges are the product of piedmont glaciers protruding repeatedly from the Aosta valley fed by the highest mountains of the western Alps.
We sampled the oldest stratigraphic units preserved at the margin, as shown.

Digging into the Mongrando till, at left, are Giovanni Monegato (National Research Council of Italy), Shantamoy Guha (GFÚ), Pierre Valla
(Grenoble), Elena Serra (Bern), Franco Gianotti (Torino). At right, Giovanni and Franco, whose in-depth knowledge of the Ivrea moraine complex is indispensable to our project.

 Days in the Eger Rift
July 2022: A couple of fun days visiting the Eger Rift and Erzgebirge mountains in northern Czechia led by David Uličný, and accompanied by our guests to GFÚ: Mike Sandiford (Melbourne) and Daniel García-Castellanos (CSIC Barcelona).

Sandstone pinnacles standing above the Labe (Elbe) gorge close to Děčín. The
blackened faces of the Cretaceous sandstone here are the legacy of atmospheric
fallout due to historical smelting works in the region.

 EGU 2022 — Vienna
May 2022: Didn't get to Vienna this year, but co-authored the following presentations with Greg:
Ruetenik et al. (2022) Large scale drainage disequilibrium in central Australia
Ruetenik et al. (2022) Understanding landscape evolution parameters using global Be-10 erosion rates.

 Back in Aarhus
April 2022: Thanks to a mobility grant from the EU & Czech Ministry of Education, I am back with my old friends at Aarhus Geoscience April-July.

A sunny day on the coast at Røgle Klint, sampling the vertically-dipping 'Elsterian' till,
with Mads Knudsen (foreground), Nicolaj Larsen and Jane Andersen (photo - Jane).

 New postdoc in the SPP research group
Mar 2022: This month we welcome Shantamoy Guha into the GFÚ Surface Processes & Palaeoclimate group thanks to a 2 yr postdoc (PPLZ) funded by the Academy of Sciences. Shantamoy will apply cosmic-ray burial dating to the oldest tills in the Ivrea Morainic Amphitheatre (northern Italy) to establish the chronology of the oldest large-scale glaciations in the western Alps.

Dr Shantamoy Guha

 Landscapes Live
Feb 2022Landscapes Live is a terrific online seminar series affiliated with the Geomorphology Division of EGU. On 24 Feb I presented a seminar 'Geomorphic legacy of a fast-moving plate' based largely on our new paper 'Geomorphic imprints of lithospheric flexure in central Australia'.

Finke Gorge, an 80 m deep epigenetic gorge in central Australia probably reflects to-and-fro tilting caused by lithospheric flexure over the

past few million years (photo M Sandiford, 2012).


 Winter fieldwork in northern Jutland
Feb 2022: Kicking off the 'First Ice Sheets' project with our first fieldwork outing to northern Jutland led by Kaleb Wagner. The weather was predictably challenging but the sun did show now and again. Coastal cliff exposures in Limfjorden allowed us to collect samples from old (pre-Eemian) till deposits for CN burial dating. 

Glaciotectonically deformed tills exposed at Knud Strand (left panel) and at Gyldendal (right panel) with Mads Knudsen, Nicolaj Larsen,
John Jansen, Greg Ruetenik, and Jane Andersen (photos - Lotta Ylä-Mella).

 Professor Paul Bishop (1949-2022)
Jan 2022: A couple of years after he examined my PhD thesis, Paul said "I wouldn't have taken it on had I known how bloody long it was, Johnno!". I joined Paul's group in 2003, and my seven years in Glasgow started me on cosmo and landscape evolution studies. Paul has been an important mentor ever since, and I will always be grateful for his guidance and no bullshit approach. He will be sadly missed.

On a handsome set of P-forms at Loch na Keal, Isle of Mull, 2003

 Czech Science Foundation funds 'First ice sheets' project
Dec 2021: Funding has thankfully been granted for our 3-yr project 'Establishing the chronology of the first great Eurasian ice sheets' led by new PhD students, Lotta Ylä-Mella and Kaleb Wagner. This project draws together an international team comprising Martin Margold (Charles), Mads Knudsen and David Egholm (Aarhus), Nicolaj Larsen (Copenhagen), Bob Anderson (Colorado), and Greg Ruetenik (GFÚ). Our aim is to resolve when large-scale Eurasian ice sheets pushed into the European Plain for the first time, and to establish whether the Middle Pleistocene Transition (~1.2–0.8 million years ago) was the tipping point for expansion of the Northern Hemisphere glaciations. Key to our investigation will be P-PINI: a newly developed sediment burial dating method based on inversion modelling of cosmogenic Be-10 and Al-26 abundances.

Says D Shrigley.

 New arrivals in the SPP research group!
Oct 2021: This month we have two new PhD researchers joining the GFÚ Surface Processes & Palaeoclimate group: Lotta Ylä-Mella and Kaleb Wagner. Both are enrolled in the PhD programme with the Department of Physical Geography and Geoecology, Charles University. Lotta has an MSc in solid Earth geophysics from the University of Helsinki, and Kaleb has an MSc in glacial geomorphology from Brock University, Canada, and spent the past 6 years with the Minnesota Geological Survey.

Lotta and Kaleb will investigate when and why the first Eurasian ice sheets advanced
beyond Scandinavia into the European Plain during the past few million years.

 Glacial Lake Agassiz megaflood during the Younger Dryas
July 2021: Out this month in Geophysical Research Letters is our new paper led by Sophie Norris 'Catastrophic drainage from the northwestern outlet of glacial Lake Agassiz during the Younger Dryas'. The results suggest a peak flood of 1.8–2.5 million cumecs with 21,000 cubic km discharged into the Mackenzie River and on to the Arctic Ocean around 13 ka.

The former floodway and now underfit Clearwater River valley (G. Back 1825).

 Neolithic farming caused abrupt soil loss in the Altiplano
May 2021: Our new paper led by Kristina Hippe 'Cosmogenic in situ C14-Be10 reveals abrupt Late Holocene soil loss in the Andean Altiplano' is published this month in Nature Communications. We show that catastrophic soil erosion coincided with wetter conditions and the transition from hunter-gathering to increasingly sedentary agropastoralism. These findings join the growing support for a strong human imprint, known as the Early Anthropocene, beginning thousands of years before the Industrial Era.

These hilltop crests have experienced an increase in erosion rate of 1–2 orders of magnitude, or a discrete stripping of 1–2 m of soil.

 vEGU 2021 — not in Vienna
Apr 2021: Co-authoring the following presentations:
Jansen et al. (2021) Geomorphic imprint of dynamic topography & intraplate tectonism in central Australia
Nørgaard et al. (2021) P-PINI: a new inversion method for sediment burial dating.

 Human migration via the Jordan Valley 
Nov 2020Our new study of a wetland that existed during MIS 5 in the rift valley includes these Levallois flakes with a minimum depositional age of 74 ± 7 ka. We argue that humans used the oasis as a stepping-stone across the desert on their way out of Africa. This study forms part of the PhD research of Mahmoud Abbas; see Al-Saqarat et al. (2021).

Levallois stone flakes dates to > 74 ka

 Open positions at the Institute of Geophysics
Jul 2020: Up to four potentially permanent research positions are being advertised here in my institute:

 Krkonoše Mountains, northern Czechia
Jun 2020: A few days of fresh air among the spruce forests and blockfields of the Krkonoše mountains, with Martin Margold (Charles U), Helen Dulfer and Ben Stoker (PhD students), and Krkonoše National Park geomorphologist, David Krause.

A 'jostled' granite tor on the summit flat and old spruce forests in a nearby cirque basin.

 Open PhD position in Prague
Apr 2020: It is well known that vast ice sheets have advanced and retreated across northern Eurasia many times over the past few million years. For instance, ~20,000 years ago the maximum extent of the last ice sheet covered the northern parts of Germany and Poland. Prior to that, however, the glaciations are poorly understood, and geologists have spent the past century trying to resolve how the distribution of ice sheets has varied over time. This research project will set out to apply a newly developed set of dating and modelling tools to unveil the history of the Early to Middle Pleistocene glaciations in Eurasia (i.e. ~ 2.6 Ma to 130 ka). Applications are invited from those with headstrong interests in numerical modelling, glacial geomorphology, and Quaternary sciences. Applicants should hold a Master’s degree or be in the final year of their studies and be able to present their Master’s degree at the beginning of their PhD candidature. Applicants with some combination of maths fluency, programming language skills, and lab experience will be strongly favoured. http://www.earthworks-jobs.com/geoscience/charles20031.html

Hardangervidda, southern Norway—a source of ice-transported clasts now found in southwest Russia?

 Lakes & fans of the Dead Sea Rift
Feb 2020: Two weeks examining alluvial fans and palaeoshorelines along the Dead Sea Rift, southern Jordan, with Paul Carling (Southampton U), Mahmoud Abbas (China University of Geosciences, Wuhan), and Leah Gibbs (Wollongong U). Funded by the Council for British Research in the Levant, our goal is to reconstruct the history of Pleistocene alluvial fan and palaeolake development arising from variable climate and tectonic drivers over the last glacial cycle and beyond. We collected a set of samples for luminescence dating and cosmogenic Be-10 and Al-26 analysis. This work will build upon Mahmoud's PhD work investigating the palaeolake deposits in Wadi Gharandal, Wadi Hasa, and Wadi Gregra.

Wadi Numeira, a spectacular slot canyon draining the eastern flank of the rift.

Sandy-clayey lacustrine sediments deposited in the ancestral Dead Sea (Lisan Lake) and preserved in a 200 m thick section along Wadi Mujib.

 Planning for fieldwork in Yakutia
Jan 2020: A short visit to Moscow to meet with collaborators and plan fieldwork in Yakutia (NE Siberia) over next July and August. The Danish Research Council-funded project is led by Mads Faurschou Knudsen (Aarhus U) and will seek to identify and date evidence of large ice sheets during past glaciations. Our expedition team includes: Nicolaj Larsen (U Copenhagen); Jan-Pieter Buylaert, and Andrew Murray (Denmark Tech U); Martin Margold (Charles U); Andrei Panin, Vladimir Tumskoy, Redzhep Kurbanov, and Natalia Vikulova (Moscow State U); Sergei Arzhannikov, Anastasia Arzhannikova, and Alexei Galanin (Russian Academy of Sciences).

The Stalinist Empire Style of the Lomonosov Moscow State University designed by Lev Rudnev and completed in 1953.

 Visit to Shantou University
Nov 2019: A short visit and lecture to the research group led by Prof. Lai Zhongping at the Institute of Marine Science, Shantou University—on China's tropical south coast.

Local fishermen at a beach nearby to Shantou.

 River-damming landslides on Minjiang River, Longmenshan
Oct 2019: A 5-day workshop organised by Prof. Fan Xuanmei (SKLGP): 'Interdisciplinary Research on Geohazards & Geoenvironment of the Tibetan Plateau' took us for three days to the Diexi palaeolandslide and other geohazard sites along the Minjiang River. We are studying the giant Diexi palaeolandslide, which has blocked the Minjiang for > 30,000 years and imposed major shifts in bedrock incision and sediment flux.

Giant ~ 250 m-high Diexi palaeolandslide (foreground & flattish area) viewed from a smaller landslide reactivated by the 1933 earthquake. Note the deeply incising knickzone (left) and the 2017 Xinmo rock avalanche, ~ 18 million cubic m (background).

Memorial to the 90,000 killed and communities destroyed by the 2008 Wenchuan earthquake, Wenchuan Earthquake Memorial Museum.

 Megafloods on Jinsha River (upper Yangtze)
Oct 2019: Following a megaflood workshop organised by Liu Weiming at the Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, we spent 5-days exploring a series of spectacular megaflood deposits along the Jinsha valley between the Daju Basin and Rongxue, Yunnan province. These include giant bars, gravel dunes, and thick sequences of suspended gravels. After the fieldtrip, along with Paul Carling (Southampton) and Daniel García-Castellanos (ICTJA Madrid), I spent a week working with Weiming and his students at CAS.

Liu Bo-Rong (China University of Geosciences, Beijing) at a ~ 20 m thick outcrop of suspended
gravels (up to boulder size) in the Daju Basin. Gravels are lightly cemented with carbonates.

High alluvial terraces near Rongxue village, Jinsha River—eastern edge of the Tibetan Plateau.

 Geofyzikální ústav Akademie věd České republiky
Sept 2019: This week I arrived in Prague to take up a senior scientist position at the Geophysical Institute of the Czech Academy of Sciences. Prague is home for the foreseeable future.

Time to get working.

 Universität Bern
Aug 2019: A week at the Institute of Geological Sciences housed within a proto-Brutalist classic from 1931—a style echoed in the 1960s at my Alma Mater, Macquarie University.

Institut für Geologie designed by Otto Rudolf Salvisberg, 1931.

Glass brick wall, Institut für Geologie.

1960s Brutalist design by Walter Abraham, Macquarie University, Sydney.

 The Deckenschotter terraces, northern Alpine foreland
Aug 2019: A set of fluvioglacial terraces extending north of the Alps, the Deckenschotter are the subject of scores of studies dating back to the days of Albrecht Penck and Eduard Brückner. Our team comprising Mads Faurschou Knudsen and Jepser Nørgaard (Aarhus) along with Florian Kober, Reto Grischott (NAGRA), and Susan Ivy-Ochs (ETH) spent a few days visiting and discussing these famous deposits with the aim of unravelling their age thanks to a new stochastic source-to-sink model known as P-PINI: Particle-Pathway Inversion of Nuclide Inventories.

A typical Deckenschotter outcrop (Tromsberg), showing coarse bar-platform gravels
with scattered sand lenses.

On Geissberg, from left: me, Jesper, Mads, Florian, and Susan. 

 On Hardangervidda, Norway
Aug 2019: A few days collecting cosmo samples from southern Hardangervidda along with Vivi Kathrine Pedersen, Jane Lund Andersen, Gustav Pallisgaard-Olesen, Jesper Nørgaard (Aarhus), Anneleen Guerts (Bergen), Maria Peter (Trondheim) and Ullrich Neumann (Kolibri Geo Services). We set about trialling our new Shaw portable core-drill kit on Gaustatoppen (1883 m) where we successfully extracted a 1.3 m bedrock core.

Across southern Hardangervidda from Vesle Nup (1510 m).

With Maria and Gustav and a splendid set of reindeer antlers near Husnuten (1609 m).

 Visit to Chengdu Geohazards State Key Lab
June 2019: A new research collaboration with Prof Dr Fan Xuanmei at the State Key Laboratory of Geohazard Prevention & Geoenvironment Protection (SKLGP). This is a new research direction for me: landscape evolution in the landslide-dominated Longmenshan. I will spend time at SKLGP as visiting professor over coming years.

The Min Jiang at the epicentre of the 2008 Wenchuan earthquake (Mw 7.9).

 2019 EGU – Vienna
Apr 2019: Co-authoring the following presentations:
Hippe et al. (2019) Cosmogenic in-situ 14C reveals rapid soil erosion with the onset of agro-pastoralism on the Andean Altiplano
Grischott et al. (2019) New age constraints of Swiss Deckenschotter constrained by cosmogenic isochron burial dating.


Kleines Café

 Eastern Desert to Venice via Constantinople
Mar 2019: To the north of Gebel Qattar in the Eastern Desert, Egypt, the Romans quarried an extremely coveted porphyry of trachyandesite-dacite composition known as Imperial Porphyry. Its restricted occurrence in just one desert valley, Wadi Abu Ma'amel, limited the use of this spectacular purple stone to imperial power. Since the fall of Rome, fragments of Imperial Porphyry have become scattered across Europe and among the most famous of these is 'The Four Tetrarchs' at the SW corner of San Marco's Basilica, Venice. This sculpture originally stood in Constantinople from ~ AD300 when the empire was ruled briefly by a tetrarchy of emperors. It was looted by the Venetians during the 4th Crusade (AD1202–1204). I visited Venice this month for the opening oOcean Space, a new transdisciplinary research centre focused on ocean conservation.

The Tetrarchs in Imperial Porphyry, Basilica di San Marco, Venice.

 Erosion & deposition in hyper-arid Egypt
Jan 2019: A return to our Khushmaan Bedouin friends in the Eastern Desert, along with Paul Carling (Southampton) and Mahmoud Abass (China Uni of Geosciences). Funded by the Centre for British Research in the Levant, our work investigates: 1) the timing and drivers of major alluviation phases recorded in alluvial fans and terraces, and 2) the long-term evolution of tall granite domes in the Gebel Qattar massif. We are building upon our previous 10Be results, which indicate catchment-scale erosion rates of ~10–40 m/Myr.

Gebel Qattar massif with 30m high alluvial terraces we sampled for OSL dating
(note Land Cruiser in foreground).

Mahmoud with plucked bedrock blocks sampled for 10Be analysis.

 Ben Lomond blockfields, Tasmania
Dec 2018: A short visit to the classic blockfields blanketing Ben Lomond plateau, northeast Tasmania.

Top-left—Exfoliation sheeting in vertically-jointed dolerite bedrock. Top-right—Thickly weathered, clay-rich regolith locally exposed beneath blockfield. Bottom-left—In situ-weathered dolerite blocks (~1 m) on the plateau. Bottom-right—fine sediments underlying gravel (deflation?) pavement.

 Professor John Chappell (1940-2018)
Oct 2018: JC left this week; a sadly missed friend and intellectual giant. Inspiring to the end, I visited him in July to work on some cosmo data from central Oz — and for a final salute. 

At his election to the Australian Academy of Sciences in 1992.

Discussing work on the Eulerian-Lagrangian reference frame for quantifying erosion, John offered this characteristic flourish:

Trying to think why Euler & Lagrange frames give such different results led me to a think of a lift in a tall building. It is at the top floor. M Lagrange enters, notes the exact time and presses the down-button. The lift accelerates then acceleration ceases, with no sensation of motion. A little later, deceleration commences, and shortly the lift stops. Lagrange has noted the exact moments of each change. The doors open; standing there is H Euler, also with stopwatch and notebook, in which he’s recorded (from the register beside the lift) the start time, the stop time, and an estimate of the velocity in the uniform-descent phase.

“Bonjour, Monsieur Lagrange”
“Guten Tag, Herr Euler”

They compare their deductions. Both agree as to average speed of the lift and, from the durations of acceleration & deceleration, M Lagrange has replicated Euler’s estimate of the velocity in the uniform-descent phase, while H Euler has determined the durations observed by Lagrange.

Now we come to another century and Emeritus Professors Euler and Lagrange are shades at large in eternity. They float together to a pleasant mountain. “I’ll rest here” says Lagrange, on a smooth granity hilltop “and imbibe the vapours of the vineyards below”. “I’m for the mineshaft” says Euler, and vanishes to a tiny gem-studded grotto below. Time passes. Lagrange amuses himself by measuring TCNs in the granite surface; Euler has measured the depth of his grotto below the surface and records the passage of Time. Seasons and millennia pass until the hilltop, reduced little by little by weather and its elements, arrives like the lift-door opening at the level of Euler’s grotto.

“Bonjour, Monsieur Lagrange. I now have an erosion rate for you. Tell me the TCN production rate and then I can estimate the surface TCN that you measured.”

“Guten Tag, Herr Euler. I have a surface TCN measurement for you. Tell me the production rate and then I can confirm your erosion rate.”

Both shades suddenly look concerned: “We neither of us know the local production rate! But we do know who does – the shade of Lal.” They call up Lal and meet at the Empyrion Cafe. They make their comparisons and everything is consistent. Phew - thank heavens!

JC, June 2018


 Alpine relief fringing the Greenland Ice Sheet
Aug 2018: Fieldwork in the Sermilik Fjord region, East Greenland, with David Lundbek Egholm, Mads Faurschou Knudsen (Aarhus), and Robert S Anderson (Colorado). We collected ~70 bedrock and sediment samples for cosmogenic 14C-36Cl-26Al-10Be analysis plus a ~2 km vertical-profile for thermochron, with the aim of unravelling the evolution of alpine relief alongside low-relief areal scour fringing the ice sheet. See this short YouTube clip of our field sites.


Alpine topography and a blockfield-capped rock pillar ~1900 m above Tasiilaq valley,
East Greenland (red helicopter for scale).

Mads Knudsen, David Egholm, Bob Anderson & John Jansen at the ice sheet margin.

 2018 EGU – Vienna
Apr 2018: Co-authoring the following presentations:
Jansen et al. (2018) Global analysis of erosional decoupling in fjord-plateau landscapes
Andersen et al. (2018) Pleistocene evolution of a Scandinavian plateau landscape
Egholm et al. (2018) Glacial erosion and relief production on gneiss-granite plateaus
Struck et al. (2018) Tracking the 26Al/10Be source-area signal in sediment-routing systems of arid central Australia.


 Siberian megafloods on the Vitim-Lena River
Mar 2018: After 7 years of grinding, the results of our Siberian adventures are now published in Quaternary Science Reviews: 'Repeated megafloods from glacial Lake Vitim, Siberia, to the Arctic Ocean over the past 60,000 years'.

Giant bar sediments (~35 ka) exposed on the Bodaybo River.

 Actively eroding high plateaus — in Nature Comm.
Feb 2018: Our new work led by Jane Lund Andersen: 'Widespread erosion on high plateaus during recent glaciations in Scandinavia' published in Nature Communications.

High plateaus from Blåhö to Rondane, southern Norway (photo: DL Egholm).

 Martin Struck submits his PhD thesis!
Dec 2017: After collecting and measuring a heroic 117 cosmogenic Be10 and Al26 samples, and then working out what it all means, Martin Struck submitted his thesis and heads to Germany this week for a well-earned break!


 Catastrophic outbursts from Lake Baikal
Nov 2017: Our work published in Earth-Science Reviews: Catastrophic events in the Quaternary outflow history of Lake Baikal

The Shaman Stone protrudes just above water-level in the southwest part of Lake Baikal.
This outcrop marks the remnants of Primorsky Ridge, whose collapse created the modern-
day Angara River outlet as recently as 13 ka.

 Associate editor at GSA Bull
Oct 2017: Rather than always whinging about journal editors, I'll soon be one at GSAB from 2018. 

 Norway fieldwork & Finse workshop
Aug 2017: A fifth season of fieldwork in Norway with the Aarhus group, revisiting sites sampled last year above Lysefjorden, plus an excellent workshop held in Finse on 'Landscape Evolution in Scandinavia' organised by Vivi Pedersen.

A sandstone pavement known as the 'Sub-Cambrian Peneplain' and lobes of the
Hardangerjøkulen ice cap in the background, southern Norway.

Attendees of the Finse workshop — just prior to heading up the mountain on an excursion led by Ivar Berthling (NTNU, Trondheim). From right: Jean Braun, Frédéric Herman, Fridtjof Riis, John Jansen, Robert Moucha, Ritske Huismans, David Egholm, Vivi Pedersen, Annina Margreth, Bradley Goodfellow, Miriam Dühnforth, Ivar Berthling, Jane Andersen, Åsne Rosseland, Anneleen Guerts, and Sofie Gradmann (with partner, Anton, and child).

 High-plateaus carved by ice — in Nature Geoscience
July 2017: Our work on glacial planation now published: Formation of plateau landscapes on glaciated continental margins


Modelled evolution of a continental margin landscape undergoing ice-sheet erosion and flexural isostasy. Topographic evolution of the subglacial landscape over time. Upper to lower panels: the initial non-glacial landscape, then after 250 and 500 kyr of glaciation, respectively. Initial landscape relief is 1 km (from 0 to 1000 m.a.s.l.). Right-side panels show the corresponding distribution of sliding velocity; frozen-bed patches with neither sliding nor erosion are shown as light areas.    

 2017 European Geoscience Union Conference (EGU) – Vienna
Apr 2017: Presenting at EGU: Jansen et al. (2017) The past 1-Myr of erosion in Fennoscandia via inversion modelling with cosmogenic nuclides.

 Back to Aarhus
Mar 2017: The Marie Curie fellowship at Potsdam came to an end, so following several research visits and combined fieldwork in Norway since 2013, I returned to Aarhus this month to take up a new research position with David Lundbek Egholm funded by the Danish Research Council.

Iconic functionalist interior of the Geoscience Institute
designed by C.F. Møller (photo: LM Gibbs).

 Sediments in Himalayan valleys
Feb 2017: Two weeks in the Annapurna Himal with Wolfgang Schwanghart (Potsdam). We set out to quantify the age and residence times of sediment in steep Himalayan river valleys in central Nepal by applying cosmo and OSL dating to river terraces and fans, landslides and glacial moraines along the Seti Khola, Madi Khola, Modi Khola and Kaligandaki.

Kahphache glacier and terminal lake at the head of the Madi Khola valley, with Annapurna II
standing 5.5 km above. The glacier receives frequent avalanche deposits, which might explain
its low elevation ~2500 masl. We sampled terminal and lateral moraines for exposure dating.

Collecting a sample from a giant boulder in the lower Madi Khola. Was this boulder
emplaced by a cataclysmic flood akin to that in the Pokhara valley in Medieval times?

 Erosion rates in hyper-arid Egypt
Feb 2017: Eleven days in Egypt's Eastern Desert, with Paul Carling (Southampton), searching for signs of palaeofloods—funded by a Thesiger Oman international fellowship. We also collected bed material cosmo samples from 16 wadis draining the spectacular Gebel Qattar (~1.5 km relief), with the aim to determine whether the extremely steep slopes of this granite batholith yield high rates of erosion under a hyper-arid climate.

Upper: The hyper-arid Gebel Qattar from near the summit of Ra's Umasar (1530 masl). 
Lower: Hammad standing among typically coarse blocks on the wadi floors. In this wadi, She'ab
Abu Teen, we collected sediments for cosmogenic nuclide analysis.

Sheikh Abdul Zahir, head of the Khushmaan Bedouins, generously shared his
profound knowledge of the Eastern Desert environment.

 Visit to Henan University, China 
Dec 2016: A week at Henan University in Kaifeng, China, where I gave a lecture and discussed plans for a new research institute, the Centre for Rivers and Civilization. I will be visiting professor at Henan University over the next 3-years.

Kaifeng old city.

 The last 1-Myr in Greenland — in Nature Communications
Dec 2016: Our new article led by Astrid Strunk: 'One million years of glaciation & denudation history in west Greenland' published in Nature Communications

Mads Faurschou Knudsen sampling a summit in northern Greenland in 2015.

 Cirques of south-west Tasmania
Dec 2016: A few days reconnaissance walking among the cirques of the Picton Range, south-west Tasmania.

Frost-driven breakup of a glacially-transported block, Picton Ra (photo: LM Gibbs).  

 Cataclysmic gravels in the Annapurna Himal
Oct 2016: Ten days fieldwork in the Pokhara valley, Annapurna Himal, with members of the Potsdam Geohazards group: Oliver Korup, Amelie Stolle, and Georg Veh, plus Monique Fort (Paris Diderot), and Tim Cohen (Wollongong). We surveyed sections, oggled the sedimentology, and collected samples for OSL and C14 dating. The Pokhara gravels (~4 cubic km) were emplaced by cataclysmic hyperconcentrated flows during a series of three Medieval earthquakes — as described in Wolfgang's Science paper Schwanghart et al. 2015.

View from Sarangkot showing 7 km of vertical relief across the Annapurna massif, with Pokhara gravel terraces in foreground.

 'Medieval Climatic Anomaly' at Bundanon
Sep 2016: The Bundanon Medieval, a science-art collaboration by Micheal and Tim Cohen, which examines the Medieval Climatic Anomaly from the perspective of the Shoalhaven river valley in SE Australia. In this site-based theatrical performance, I played a 'whirling wand' in a piece of improvised music led by Dutch composer, Cor Fuhler.


 On the plateau above Lysefjorden, Norway
Jul-Aug 2016: A successful start to fieldwork on the new FROST project: One week collecting cosmo samples and flying drones above Lysefjorden in southern Norway with David Lundbek Egholm and Sofie Vej Ugelvig (Aarhus), Vivi Pedersen and Henriette Linge (Bergen). A short drone movie of our field site (compiled by DLE): Lysefjorden, Norway

L—Vivi and Sofie sampling rock surfaces. 
R—Glacially scoured areas above Lysefjorden, the focus of our sampling.

 FROST funded by Danish Research Council, DKK 6 million
Jun 2016: Funding success for FROST (2016-19): 'Formation of summit flats in cold-region topography' led by David Lundbek Egholm and the Aarhus group. Thanks to this boost we will extend our work on the North Atlantic margins of Norway and Greenland along with team members from Bergen, Glasgow, Dalhousie, Colorado, Stockholm, and Potsdam universities.

 30 years of counting atoms ...
Jun 2016: About 70 scientists 'celebrating 30 years of counting cosmogenic atoms' came together at the 3rd Nordic Workshop on Cosmogenic Nuclide Techniques in Stockholm. I presented a paper on radionuclide inheritance and co-authored several presentations by Aarhus colleagues: 
Andersen et al. (2016) Blockfields in Reinheimen ... Neogene weathering remnants or Quaternary periglacial origin?
Andersen et al. (2016) Landscape preservation under ice? In situ 10Be and 26Al from summit surfaces along Sognefjord, Norway.
Jansen et al. (2016) Windows on erosion rates under polythermal ice in Fennoscandia ...
Knudsen et al. (2016) Constraining detailed glacial history by inverse modelling of paired multiple cosmogenic nuclides.

Glacial striations on bedrock near Forsmark where many of us travelled the day after
the workshop to view the nuclear facility and planned repository for nuclear waste. The
question here is: How fast is this landscape eroding? And will nuclear waste stored 500 m 
deep be secure for hundreds of thousands of years to come?

 Arrhenius Lectures, Stockholm
Apr 2016: At Stockholm University to present three lectures funded by the 'Svante & Maria Arrhenius Fund': i) Glacial outburst floods from interior Eurasia to the Arctic Ocean, ii) Basin sediment dynamics in central Australia: tectonic & climate drivers from source to sink, and iii) Evolution of mountain topography at North Atlantic margins.

'Neotectonics on the Australian Plate' at Geoscience Australia
Feb 2016: A symposium hosted in Canberra by Geoscience Australia and the Melbourne Energy Institute. I presented a paper on cosmo-derived erosion rates in the Eyre Basin: Jansen et al. (2016) Erosion and the sediment conveyor in central Australia.


  Flume experiments at the Changjiang River Institute
Nov 2015: A visit to Wuhan, China, to oversee ongoing flume experiments at the Changjiang River Scientific Research Institute, which aim to understand the sediment transport dynamics of anabranching rivers. Postdoc Caiyun Deng has calibrated a 50 m-long flume constructed especially for our experiments, and is now testing the sediment transport efficiency of single- and anabranching channels of varying width/depth ratio.

L—Upstream view of 50 m flume: the 6 m single-channel splits into 2 x 2 m anabranches. Q = 300 l/s, note sinuous-crested ripple bedforms.
R—Removal of 2 m-wide bedload trap fitted at the end of each channel. Bedload (blue polymer grains ρ=1.3 g/cm3) yield is weighed hourly.

Deglaciation of Fennoscandia: The Movie
Oct 2015: A neat 17-sec movie included in our recent QSR paper, Stroeven et al. (2016), which documents the demise of the Fennoscandian ice sheet since ~22,000 years ago.


Modelling landscapes
Oct 2015: Symposium on landscape evolution modelling hosted by the Volkswagen Foundation at Herrenhausen Schloss, Hannover: 'Bridging the gap between field evidence and numerical models'. I gave a keynote lecture: Eroding mountains at high latitudes.

  
 GeoBerlin 2015 – Freie Universität Berlin
Oct 2015: Joint conference of the Deutsche Geologische Gesellschaft/Geologische Vereinigung (DGGV) and Deutsche Mineralogische Gesellschaft (DMG) celebrating the 100th anniversary of Alfred Wegener's seminal publication: Die Enstehung der Kontinente und Ozeane (The Origin of Continents and Oceans). I co-authored the following presentations: 
Jansen et al. (2015) The cold-climate origins of Scandinavian mountain plateaux
Struck et al. (2015)* Quantifying sediment transport time and burial duration in central Australian low-gradient landscapes ... 
*Martin's poster won the Student's Choice Award and was ranked 2nd in the DGGV Student Poster Award!

Wegener

Svante & Maria Arrhenius Fund 2015
Sep 2015: Thanks to Sweden's Svante and Maria Arrhenius Fund, I will present a series of lectures next spring at Stockholm University on my favourite topics.

Frost action on Reinheimen, Norway
Aug 2015One week in the Kjølen mountains (Reinheimen) collecting cosmo samples and conducting geophysical surveys of the regolith mantle with David Lundbek Egholm, Jane Lund Andersen, Kristoffer Andersen, and Helle Holm (Aarhus). Here and elsewhere in Scandinavia we are seeking to understand how periglacial processes influence the evolution of mountain plateaux over million-year timescales.

Reinheimen: a sea of blocks (left), and periglacial stone circles (2-3 m diameter) viewed from a helicopter (right).

Kristoffer and Helle with the electrical conductivity meter, which we used to estimate the
thickness of the regolith mantle.

 2015 International Quaternary Research Congress (INQUA) – Nagoya, Japan
Jul-Aug 2015: Co-authoring the following presentations:
Andersen et al. (2015) Modelling the long-term periglacial imprint on mountain landscapes
Cohen et al. (2015) Rethinking the cold, dry LGM in central Australia
Cohen et al. (2015) SHAPE – Australia 60-30 ka
Eccleshall et al. (2015) Sediment dynamics of a large, dryland river catchment, central Australia
Fujioka et al. (2015) Long-term waterfall dynamics in monsoonal Australia based on cosmogenic Be-10
Jansen et al. (2015) Topographic legacy of mountain glaciation in the Scandinavian mountains
Knudsen et al. (2015) A multi-nuclide approach to constrain landscape evolution ... in previously glaciated terrains
Larsen et al. (2015) Quantifying hydro-climatic changes consistent with water and energy balances over Quaternary timescales
Martin et al. (2015) Uranium comminution dating in slowly eroding, tropical Australia
Stroeven et al. (2015) Deglaciation of Fennoscandia
Struck et al. (2015) Sediment transport dynamics in central Australian low-gradient landscapes.


'High plateaux' in popular media
Jul 2015: At Home on High Plateaux... University of Potsdam magazine article 
Zu Hause in wettergegerbten Gebirgen Märkische Allgemeine Zeitung (newspaper article, in German).

Fieldwork on the Finke, Central Ranges
Jun-Jul 2015: Perambulating around the Finke River system, central Australia, with Toshi Fujioka (ANSTO), Tim Cohen and Martin Struck (Wollongong), plus visitors Bob Anderson and Suzanne Anderson (Colorado). The Finke River system is new territory for us; we have three main goals: 1) measurement of cosmogenic 26Al/10Be in fluvial and hillslope sediment — part of Martin Struck's PhD project, 2) a 10Be-based chronology of the palaeo-Finke as recorded in abandoned bedrock meander loops, and 3) a revised palaeoflood history of the Finke River, which feeds to Lake Eyre.

Bob and Martin contemplating bedrock abrasion in Ellery Ck gorge (left). Strolling through a ?Miocene palaeo-valley in Finke gorge (right).

DEM image of the Finke River gorge showing its intertwining bedrock palaeo-loops (L) at the Ellery Ck junction (many thanks to Geoff Pickup for the TOPSAR DEM). The palaeo-loops stand ~25 m above the modern gorge floor and preserve fluvial gravels, which we sampled for 26Al/10Be analysis. Pickup et al. (1988 — Fluvial Geomorphology of Australia) suggests that these palaeo-valleys might be Miocene in age!

Genyornis in art!
Apr 2015: Vienna-based artist, Anna Stangl, will exhibit her new work inspired by tales of the extinct giant bird, Genyornis (see Cohen et al. 2015) this month at Galerie Schafschetzy, Graz, Austria.

Genyornis aka 'the giant goose'

2015 European Geoscience Union Conference (EGU) – Vienna
April 2015: Co-authoring the following presentations:
Jansen et al. (2015) Cirque-driven erosion of the Scandinavian mountains
Eccleshall et al. (2015) Basin-wide sediment interactions ... in a large, dryland river system, central Australia
Struck et al. (2015) Sediment dynamics in flat landscapes – insights from central Australia.
On my way back to Potsdam I gave an invited lecture at the Quaternary Research Group, University of Innsbruck, on the Glacial Lake Vitim megafloods.

Late Holocene megafloods in the Annapurna Himal
Mar-Apr 2015: 3 wks fieldwork in the Annapurna Himal, Nepal, with the Potsdam Geohazards group: Wolfgang Schwanghart, Anne Bernhardt, Amelie Stolle, and Miriam Roschlaub. This work forms part of Amelie Stolle's PhD research on the nature and origins of 4 cubic km of coarse-gravel deposits ejected from the Annapurna massif into the Pokhara valley ~800 years ago.

Machhapuchchre above Pokhara, Nepal.

80m-high terrace exposure of fluvial and debris flow gravels.

Climate change coincided with megafaunal extinction
Feb 2015: Our study of ancient shorelines along lakes Eyre and Frome in central Australia shows that major hydrological changes were occurring prior to and just as the giant bird, Genyornis newtoni, went extinct ~50–45 kyr. These new results (Cohen et al. 2015) strongly implicate climate in central Australian megafaunal extinction and cast doubt on previous arguments for a simple human-mediated 'ecosystem collapse'. See also articles in Nature Research Highlights, The Guardian, and our accompanying essay: Drying inland seas probably helped kill Australia's megafauna published in The Conversation.

Madigan Gulf, Lake Eyre, under present-day playa conditions, August 2014.

Blockfields & loess in the Southern Alps
Jan 2015: A visit to New Zealand's Southern Alps, where at the Mt Somers rhyolite dome we came across thick saprolites (>5m) and a summit blockfield blanketted with loess (wind-blown dust deposits). This raises the question of how loess might contribute to frost-creep transport on blockfields?

Mt Somers summit blockfield: under the tussock grass the blocks are swimming in loess,
and becoming exposed only in steeper areas where the loess is washed out.

 2015-16 Marie Skłodowska-Curie Fellowship in Potsdam
Dec 2014: This month I took up a 2-year fellowship working with Oliver Korup and his Geohazards group at the Institute of Earth & Environmental Science, University of Potsdam. The project will extend my work on how cold-climate processes influence the topography of postorogenic mountains.

Park Sanssouci, Potsdam

New Wollongong cosmo lab
Nov 2014: Our new Wollongong laboratory for cosmogenic nuclide analysis, led by Alexandru Codilean, saw its first batch of samples processed this month: sediment and bedrock collected on our winter trip west of Lake Eyre. Samples will be measured for Be10 and Al26 next month at the ANSTO-AMS facility.

First hot doggin' samples!

 Fieldwork west of Lake Eyre, arid central Australia
Aug 2014: The UOW-ANSTO team, sampling for cosmogenic nuclide analysis and OSL dating at Lake Eyre, along the Neales and Macumba river systems, and in the Davenport, Flinders and Barrier ranges. This fieldwork forms part of Martin Struck's PhD research, which aims to quantify the rate of the 'sediment-conveyor' from hillslope regolith production to floodplain storage in large river systems of arid Australia.

The UOW-ANSTO team on the crest of the Davenport Range (from left): Sarah Eccleshall,
John Jansen, Réka-Hajnalka Fülöp, Alexandru Codilean, Martin Struck, Toshi Fujioka, and
David Fink. 

Flat gibber plains W of Oodnadatta; such surfaces make up a large proportion of arid 
Australia. To quantify the residence time of sediment we excavated pits and sampled for
OSL dating and cosmogenic nuclide analysis.

Mountain plateaux: uplifted remnants or cold-climate forms?
May-Jul 2014: A research visit to the Department of Geoscience, Aarhus University, working with David Lundbek Egholm, Mads Faurschou Knudsen, Jane Lund Andersen, Sofie Vej Ugelvig, Vivi Kathrine Pedersen (Bergen), and Bradley Goodfellow (Stockholm) on the origins of mountain plateaux in the Scandinavian mountains.

Sampling bedrock surfaces for cosmogenic nuclide analysis, above Sognefjord, Norway.

Gorges cut by melting ice sheets
May 2014: Our work on subglacial gorges published in Nature Communications: Jansen et al. (2014) [Supp.data]. See also media articles: Origin of Scandinavian gorges... and Rivers under ice sheets...

Bedrock inner gorges were carved by subglacial meltwater during
the last deglaciation in N Sweden. Postglacial rivers have achieved
negligible erosion in this landscape (Photo: G Bength).

2014 European Geoscience Union Conference (EGU) – Vienna
Apr 2014: Co-authoring the following presentations:
Jansen et al. (2014) Rivers under ice: fluvial erosion beneath decaying ice sheets
Cohen et al. (2014) Vanishing megalakes in central Australia coincided with megafaunal extinction ~48 ka
Margold et al. (2014) Late Pleistocene glaciation of the Kodar Mts, south-central Siberia, constrained by Be10.

Channel country fieldwork: The roots of anabranching
Sep 2013: Sampling Cooper Ck sediments for OSL dating and cosmogenic Be10-Al26 measurements, as part of Sarah Eccleshall's PhD research (Wollongong). A key objective is to constrain the timing of the inception of anabranching in arid Australia: Was the transition climate-driven?

Sarah and 'Driller Joe' on the Cooper Ck floodplain near Windorah, E-central Australia.

Dry channel anabranch on Cooper Ck near Windorah.

Norway fieldwork: Evolution of high plateaux
Aug 2013: Collecting samples for measuring cosmogenic Be10-Al26-Ne21 accumulated on summit surfaces in the Scandes mountains, with David Lundbek Egholm and Mads Faurschou Knudsen (Aarhus). This work forms part of Jane Lund Andersen's PhD research, which aims to determine denudation rates on high plateaux in western Scandinavia and to what extent these landforms predate the Quaternary.

Sampling fluvial sediment derived from summit blockfields on Storlifjell massif, S Norway.

Hestebotten glacial trough viewed from Gråskarvet summit, 1720 m asl, with the
extensive Storlifjell blockfield in foreground.

Changjiang River Scientific Institute, Wuhan
Jun 2013: A visit to the CRSRI flume facility in Wuhan, China, to plan experiments on the dynamics of anabranching.

Down-scaled (1 km long) model of the lower Changjiang (Yangtze) River.

Harsprångsfallet: Then & now
One of our inner gorge field sites, Harsprångsfallet, features the highest knickpoint (75 m) in northern Sweden.

Harsprångsfallet, before and after construction of the hydro-electric dam in the 1950s.

Harsprångsfallet (also known by its Sámi name Njommelsaska) illuminated by the aurora
borealis—a chromolithograph by Carl Svante Hallbeck (1856). Despite appearing to be a
highly erosive fluvial environment, this steep inner gorge emerged virtually fully-formed
from under the retreating ice sheet at 10.0 ka, and has subsequently undergone just a
few metres of bedrock incision.

2013 European Geoscience Union Conference (EGU) – Vienna
Apr 2013: Co-authoring the following presentations:
Jansen et al. (2013) Lowland river response to intraplate tectonism and climate since 270 ka
Margold et al. (2013) Reconstructing Glacial Lake Vitim and its cataclysmic drainage to the Arctic Ocean.

Eroding southern Africa
Mar 2013: Our work on the Cape Mountains published in Geology: Scharf et al. (2013) and on Our Amazing Planet.

South Africa's Cape Mountains are eroding more slowly (2–8 m/My) than any other 
landscape of similar steepness and relief (>1500 m).

2013-15 ARC Discovery grant, AU$380k
Dec 2012: 'Anabranching Rivers; the Arteries of Arid Australia' — a collaborative research project with Gerald Nanson (Wollongong), David Fink, Toshi Fujioka (ANSTO), and He Qing Huang (Chinese Academy of Sciences). The anabranching (multi-channel) river pattern dominates the world’s largest lowland rivers and vast areas of arid Australia, yet no comprehensive explanation exists for why this is so. Anabranching remains the last river style to be fully investigated, though millions rely upon and live alongside them. A field-study of major Australian anabranching rivers, including their flow and sediment flux properties, will be coupled with drilling and dating the rich fluvial archives buried beneath them. Insights from these field-studies will be used to guide and calibrate a set of laboratory flume experiments in Wuhan, China, aimed at determining the fundamental boundary conditions that cause this enigmatic river style.

2012 Australia & New Zealand Geomorphology Conference
Dec 2012: Bundanoon, Keynote Lecture: Erosion in Cold Landscapes.


Siberia fieldwork: Cataclysmic glacial outburst floods
Aug-Sep 2012: Glacial Lake Vitim/Muya River & Kodar Mountains, Transbaikalia, with Martin Margold (Stockholm) and Artem Gurinov (Lomonosov-Moscow); a follow-up on our 4 wks work in Siberia in Aug 2011:
● sampling 10Be depth profiles in giant flood bars (>200m above the valley floor); 
● Be10 sampling moraines around the ice-dam to constrain the age of the glacial outburst flood;
● OSL sampling varved lacustrine muds exposed on the Muya River — we suspect these are linked to a long-lived lake in the Muya Basin, perhaps the same lake that burst through the ice-dam;
● OSL sampling from sandy deltas on a large palaeolake east of Lake Baikal, with Anastasia Arzhannikova and Sergey Arzhannikov, Russian Academy of Sciences.

The 3000 cubic km Glacial Lake Vitim (pink) formed when glaciers blocked the path of
the Vitim River. Collapse of the ice-dam caused a major influx of freshwater to the Arctic
Ocean via the Lena River. We are working on determining the timing and magnitude of
this megaflood.

Vitim River at Nerpo ~100 km downstream of the postulated ice-dam, September 2012.

 Central Australia fieldwork: Vanishing desert megalakes
Jul 2012: Lower Cooper & Warburton Cks, with Tim Cohen, Henne May, Luke Gliganic (Wollongong) and Toshi Fujioka (ANSTO):
● OSL sampling late Pleistocene sediments (Katipiri Fm);
● Be10 sampling Plio-Pleistocene Kutjitara and Tirari Fm outcrops.

Looking upstream from Kutjitara West Bluff, lower Cooper Ck, July 2012.