EGU 2021 - Glaciation in the High Atlas

We're at vEGU21, and Ben and Henk will be giving presentations to update on the project, this coming Thursday (29th April 2021).

If you can't make the conference, you can find the live 2 minute (single slide) and full display materials for both presentations on the website.

To kick off, Ben will be giving an overview of the project and where we are following delays caused by COVID, including new moraine boulders dated sent off for cosmogenic dating, and new palaeoenvironmental records from the area.

This will be in the GM7.7 session, on Thursday 29th at 09:41 CEST (08:41 BST). You can read the full abstract and access the display materials here, or see below!

EGU 2021 - Live presentation slide

Summary of the project. Figures show select pollen and micro-charcoal from Oukaimeden, current and future cosmogenic dated boulders/moraines in the region, and the Neve Permanent.

Presentation transcript (2 minutes):

Hi, good morning everyone.

Today I am going to talk about our project in the High Atlas, Morocco, where we are investigating climate and environmental change.

We are looking at the geomorphology of the area, where we are mapping and dating glacial features … and, we’re also investigating the palaeo-environmental history through proxies such as pollen.

The aim here, is to compare the timing of ice expansion with the palaeo records, so that we can understand the impact on the environment, but also, how this influenced human activity and occupation of the area.

So far, we have collected 42 new rock samples for cosmogenic dating from moraine boulders, which you can see on the map, alongside our existing dated moraines. These samples are currently being processed at ANSTO, and we hope to get the results back soon. We are expecting to get some Little Ice Age dates, near to Tazaghart where there is permanent snow today.

On the palaeo-environmental side, we have two new multi-proxy records.

The first one at Oukaimeden covers the last millennium, and in this we see changes in direct response to the Little Ice Age.

This includes increased wetland taxa as a result of enhanced snowpack. And, we also observe a reduction in tree pollen with a corresponding increase in charcoal, now this could suggest a human response to cooler climate conditions.

The second record at Yagour Plateau covers the entire Holocene and Late-glacial period. And, if you want to know more about this work, my colleague Henk is presenting later this afternoon, so do check that out.

Okay, so that’s a really brief summary of our project.

Thank you for listening.

For more details on the slide, check out the full presentation below.

EGU2021 - Slide 1

EGU2021 - Slide 2

Full details of glaciation and cosmogenic dates in Hughes et al. 2014; 2018, and 2020.

EGU2021 - Slide 3

EGU2021 - Slide 4

Snow patches or late lying snow is indicated by the white circles in the close-up maps. The numbers refer to their name/location, which is available in the published paper (linked below). Data compiled from fieldwork and satellite imagery.

EGU2021 - Slide 5

The Neve Permanent – the only permanent snow patch (survives all year) in the Marrakech High Atlas. This picture shows the patch in September 2019, following a generally warm summer. There are many records (including photographic) of this snow patch at different times of the year during the 20th century.

EGU2021 - Slide 6

Most of the dated boulders/moraines are Late-glacial or Pleistocene, along with some Younger Dryas records. Some boulders were dated to Holocene, but these were considered outliers as they were found on Pleistocene moraines lower in the valleys.

We hope to test these hypothesis with the new cosmogenic dataset, and new high-resolution palaeoenvironmental records.

EGU2021 - Slide 7

Location of the existing dated moraine boulders (white diamonds with colour borders) and the boulders which we have sampled for dating and are currently being processed.

EGU2021 - Slide 8

New palaeoenvironmental record from Oukaimeden suggests both human and environmental response to enhanced snowpack during the Little Ice Age. Full details will be available in our new paper (due out very soon!) in Vegetation History and Archaeobotany.

EGU2021 - Slide 9

This shows selected pollen, wetland, NPP and micro-charcoal data from Oukaimeden. At the bottom of the core, during the Medieval Warm Period (MWP) we have reduced wetland taxa, increased soil erosion and disturbance. As we move into the Little Ice Age, wetland taxa increases significantly, and we also see corresponding increases in micro-charcoal, and reductions in tree pollen. At the very top of the core, for the last century, tree cover increases quite a lot due to plantations (Pine, Cedar), and we also see increased micro-charcoal and grazing activity.

EGU2021 - Slide 10

EGU2021 - Slide 11

The lake at Yagour Plateau, and coring Moroccan style.

EGU2021 - Slide 12

EGU2021 - References

Links to each paper:

Bell, B. A. et al. (2021). (In Press - link coming soon!)

Hughes et al. (2018)

Hughes et al. (2014)

Hughes et al. (2020) (Open Access).

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