Mission Possible: Scoat Tarn Boot Camp

By Fiona Russell (PhD researcher and Graduate Teaching Assistant)

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2st July 2014, the day we conquered Scoat Tarn!

Your mission, Fiona Russell, should you wish to accept it is…… compile a group of eight willing volunteers, two boats, paddles, 8 life jackets (must be safe), two corers, 350m of rope, 10 litres of drinking water, a ladder, some dodgy knees, sunshine and some cling film, then tackle one of the highest lakes in the Lake District to recover 1000 years of mud from beneath 18m of water. This message will self-destruct in 30 seconds.

After some last minute alterations due potential 40 kph winds on Thursday, we set off for an epic coring trip to Scoat Tarn, a typical mountain cirque basin at 600m altitude in the Lake District National Park, UK. Scoat Tarn is small (5.2ha), deep (<20 m), lies in a west facing valley at an altitude of 602 m to the north and above Wastwater, England’s deepest lake. The catchment comprises steeply sloping walls; with summits in excess of 825 m. Scoat Tarn shows a sediment signature of severe acidification in recent years as a direct result of human-induced acid deposition, and the location is one of the UK Upland Waters Monitoring Network of sites, whose data show the lake has recovered to some extent the last two decades.

Seven of the group sensibly met at the Wasdale Head Inn where we set up camp and spent an enjoyable evening in the pub eating drinking and watching Belgium knock USA out of the World Cup. The eighth decided to play a league tennis match til 8.30pm and then drive to the Lake District arriving just in time for last orders and a welcome pint of Lakeland Ale already purchased by the team.

In the morning, after a quiet night’s sleep accompanied by incessant bleating sheep, squawking birds, cuckoos and general noisy countryside, the reality of it all struck home and the tough fieldwork we had come here for arrived. A short drive along the edge of Wastwater and we arrived at the car park. Eight rucksacks packed to the brim with boats, ropes and coring equipment, we set off into the hills for a slightly daunting 500m climb over 4km.

Several hours and several miles (or km) later we reached Scoat Tarn. The aim was to collect 3 short gravity cores and a longer sediment record using a piston corer. To get the latter, we had to set up a rig with a stable working area from which we could operate the piston from. Our design was successful (it was worth carrying the ladder all that way!) and we managed to extract a one meter core from 18 m of water that will probably encompass the last 1000 years of environmental history for this upland catchment and what a catchment a stunning cirque basin in the southwest fells of one of the most beautiful valleys in England…..

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We returned home to Liverpool the next morning with bags of sediment and a huge sense of achievement, my first PhD samples in the bag! Thanks to the team; Richard Chiverrell, John Boyle, Daniel Schillereff, Jen Clear, Hugh Smith, Amy Lennard and Agata Marzecova.

Western Ireland Excursion: the Grand finale of the DYNAMITE project (DYNAmic Models in Terrestrial Ecosystems and Landscapes)

Connemara coastline, stunning bays, headlands and sea food

Connemara coastline, stunning bays, headlands and sea food

The four-year DYNAMITE project (DYNAmic Models in Terrestrial Ecosystems and Landscapes), a teaching and research cooperation programme between the School of Environmental Sciences, University of Liverpool, UK and the Departments of Geology and Physical Geography and Ecosystem Science at Lund University, Sweden, recently ended with an excursion for PhD students, postdocs and academic staff from both institutions to western Ireland in September 2013 and organised magnificently by Prof Richard Bradshaw (University of Liverpool).

A brief report from the trip offers an excellent overview of the breadth of Quaternary Science as a discipline, illustrating how we integrate geomorphology, archaeology, geology and palaeoecology, to foster better understanding of local- to global-scale environmental change at varying temporal scales through the Holocene and Pleistocene.

Archaeology

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Our trip began (Day 1) in The Burren, an extensive karstic landscape composed of remarkable limestone pavements and that supports many rare species. Michael Gibbons guided us around a number of fascinating archaeological sites, many of which feature in this detailed report from the Burren Landscale and Settlement Project. We visited impressive hill forts, court tombs and exposed oyster middens, many of them dating from Neolithic, and in some cases Mesolithic age. Many sites in the Burren have yet to be excavated, including these stone piles in the tidal zone; what was their purpose and when were they constructed remains to be discovered.

The trip also ended (Day 6) discussing archaeology, specifically the Céide Fields Neolithic complex at Ballycastle, County Mayo. These field systems enclosed by stone walls represent the most extensive Neolithic Stone Age monument in the world, dating to 5000 – 6000 years ago, and is today mostly covered by extensive blanket peat except for a few isolated areas currently undergoing excavation. The age of the walls is determined by applying radiocarbon dating to fossilized pine stumps preserved in the bog. Seamus Caulfield (Archaeology, University College Dublin) who has focused much of his research career on these sites led an extensive guided tour of the excavations, where the peat has been removed at various intervals revealing the abandoned stone walls.

While individually the piles of stone do not initially appear tremendously impressive, when the spatial extent (>10 km2) and perfectly parallel construction of the walls is considered, the enormous scale of Neolithic agriculture in the region is unveiled. What is also of great interest is the rarity or lack of preservation of a monument of similar age elsewhere in northwest Europe. It appears most likely that a regional decline in pine forests (indicated by pollen reconstructions) meant stone walls were constructed at great effort, instead of the log walls constructed from forest timber at the time elsewhere in Europe.

Palaeoecology

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A short boat ride on Day 2 took us to Inis Oírr, the smallest of the Aran Islands, led by Karen Molloy (National University of Ireland, Galway). The small field boundaries struck me as unusual but apparently such land division has a long history in western Ireland (as we discovered at the Céide Fields). Karen presented the impressive lake sediment sequence of An Loch Mór; the unique setting of the lake means the >13 m of sediment deposited here records a fascinating story of palaeoecological change (e.g., Holmes et al. 2007, QSR) through the late-Glacial and Holocene periods, including insight into local ice retreat at the end of the last glaciation, sea-level and salinity changes, vegetation history and phases of exceptionally high windspeed due to its exposure to the Atlantic Ocean.

Later in the trip (Day 4) we tracked down a small exposed organic deposit exposed in a fluvial terrace at Derrynadivva that contained many large plant macrofossils. It turns out these deposits are not Holocene in age; rather, they are remnants of plants growing during a previous Pleistocene interglacial. It remains uncertain which interglacial is represented here however based on analysis of the pollen and plant macrofossils, the deposit possibly represents Oxygen Isotope Stage 11 (Hoxnian; e.g., Coxon et al. 1994 JQS).

Glacial Geology and Geomorphology

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We visited a number of sites around Co. Galway, Co. Mayo and Connemara (Days 3 – 5) with Professor Peter Coxon (Geography, Trinity College Dublin) and Dr Richard Chiverrell (Environmental Sciences, University of Liverpool) to examine the complex, fascinating and still-unresolved history of Late Glacial ice-retreat in western Connemara. The stunning landscape of Connemara bears vast evidence of ice-sculpting during the last glacial period, including the elongated fjord of Killary Harbour, the Twelve Bens mountain massif that rises almost directly from the sea and the partly submerged drumlin field at Clew Bay.

The Ballyconneely Bay drumlin was particularly impressive with excellent coastal erosion exposing the innards of the feature with a length-wise cross-section through the middle of the drumlin. One can thus walk along the beach examining its internal sedimentology in great detail. The sharp contact to angular facies at the head of the drumlin, suggesting coarse debris flow / meltwater processes that occurred in a cavern beneath the icesheet, was especially neat.

We visited quarries at Tullywee cut into a subaqueous fan fed by a series of anastomosing eskers related to ice retreat from the last glacial maximum (~25 k years ago) that imply a water-surface of 60-65 m above IOD. In addition the large ice-contact deltas at Leenaun at the fjord head of Killary Harbour and exhibit a classic Gilbert-style structure implying a high shore-level of 78 m IOD. Further deltas were visited at Srahlea Bridge and in the Glennacally Valley, you can never have too many deltas. The causal mechanism(s) for this high water-levels have yet to be fully deciphered, but probably relate to ponding of lake waters in and against the mountains of Connemara by more dominant ice orginating the Irish Midlands and penetrating through and around the Connemara Mountains via Galway Bay, Killary Harbour and Clew Bay, whilst the mountain glaciers were in a reduced state during deglaciation (~20 – 18 k years ago) . This hypothesis seems more plausible than the alternate glacio-marine hypothesis which requies much higher local sea-level than models or other reconstructions possibly suggest. More discussion of these implications can be found in Thomas & Chiverrell, 2006 Quaternary Science Reviews.

Many pristine examples of glacial geomorphology were observed during the trip, for example the eskers at Tullywee, as well as much smaller features such as this ‘dropstone’ in a small exposure in the Leenaun delta. One could easily stroll past and not realise the significance of this cobble; the deformed sediments indicate we were adjacent to a calving margin and this cobble exited the iceberg as it floated seawards and was deposited in the soft sediments. The precise timing and rates of ice retreat in this part of the world are the subject of on going research in the NERC Consortium Project BRITICECHRONO.

Summary

It was a wonderful trip, tremendously educational and certainly a place I’d love to visit again for its visual beauty and ideally for the purpose of research as there is much yet to be understood about the Quaternary environments of western Ireland. For interested readers, the Quaternary of Central Western Ireland (edited by Professor Pete Coxon, 2005) contains a wealth of further information on many of these sites and other case studies.

Mostly written by Daniel Neame Schillereff

Dan Schillereff waxing lyrical #guinnesshelps

Dan Schillereff waxing lyrical #guinnesshelps

The GPG Experience

Hi.  We’re Elle and Jess.  We’re in our third year of the Geology and Physical Geography (F6F8)BSc degree – affectionately known as ‘GPG’.  Over the summer, the two of us spent three weeks in Cornwall working on our Honours projects.  Elle’s project focuses on the record of Quaternary climate and sea-level change preserved in the cliff sections of Godrevy.  Jess’ project is a study of the Holocene evolution of the coastal lowlands near Gwithian.  We were out in all weathers recording the cliff exposures, coring through the sands, clays and peats of the Red River floodplain, and noting the characteristics of the contemporary beach sediments.  It was a real challenge – both mentally and physically – to get the work completed, but it was really worth it.  We both feel that we’ve achieved a huge amount as a result of our independent fieldwork and follow-up analysis.  It is perhaps the first time where we feel we’ve been a part of the geosciences research community.

That’s us – Elle and Jess – doing what we do best: fieldwork!

Following the field, laboratory and library research, we’ve just completed our Honours project presentations where we give a 15 minute summary of our research findings and how they address our stated project aims.  It was a traumatic experience presenting our results and being quizzed by our fellow students and staff – but it has been really useful in bringing together our ideas on our respective projects.

There is no doubt that the GPG degree is a fantastic opportunity to specialize in geomorphology, sedimentology and the ‘softer’ and applied areas of geology.  We’ve had a great time in learning new material, and in having direct experience of this in the field.  Fieldwork has been probably the best part of the programme – and we’re really looking forward to the 2-week Almeria fieldtrip at Easter in 2013.

The GPG degree has a long history at Liverpool – and it is great that it is a coherent programme accredited by the Geological Society.  This offers us a real advantage, when it comes to jobs, over similar people who have studied either joint or combined degree programmes at other Institutions.  Famous graduates from the GPG programme include, amongst many others, David Hodgson (Reader in Applied Sedimentology at Leeds), Tom Bradwell (Quaternary Geologist at the BGS), Tom Hill (Museum Scientist at the Natural History Museum) and Ian Selby (Head of Minerals and Infrastructure at the Crown Estate).

Year 1 Geology and Physical Geographers on a weekend in Snowdonia 2012

Over the weekend of 20-21st October Year 1 students from the School of Environmental Sciences set off for some autumn fun and relaxation in the mountains of Snowdonia, a parallel trip to the Trawsfynedd weekend taken by Geography, Ocean Science and Ecology students. A happy bunch of Year 1 Geology and Physical Geography (GPG) students, along with fellow year 1 students on other Geology and Geophysics

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degrees and ~9 lecturers to spent two days gallivanting around Cwm Idwal and for some another large hole in the ground (quarry).  Cwm Idwal, a large amphitheatre calved by erosion by ice during the repeated glaciations of the last 2 million years was at its stunning best in the autumn sunshine.

On Saturday after an early start from Liverpool we all congregated at the Llyn Ogwen car park at the foot of the Carneddau and Glyderau mountain ranges. From there Pete Kokelaar led a magical mystery tour through the turbulent volcanic history displayed in the rock record. The geology shows the deposition of huge pyroclastic flows from volcanic eruptions into a marine basin ~450 million years ago, and these strata have been deformed into a large syncline in subsequent mountain building. Outcrop after outcrop were crawled over from the head of the Nant Ffrancon to the foot of the Idwal Slabs. Overnighting in Caernarvon with a good meal, some pretty good beers, vividly colored and tasting shots courtesy of the students (thanks I think…), views of many members of the local constabulary and UK Borders Agency, and some bizarre speckley green-red glitter-ball lighting effects in the chosen hostelry playing havoc with Alan Boyle’s attention span later, a good night’s rest was had by some……

On Sunday the GPG students gained their first immersion into the wonderful world of glacial geomorphology and coring of lake sediments to reconstruct past environments with Rich Chiverrell and Jim Marshall. After a quick introduction to the broad landscape components, the skills of triangulation and geomorphological mapping were introduced, before 2-3 hours of mapping the retreat moraines of the last glaciation to have affect Cwm Idwal 12,600-11,500 years ago. The afternoon saw a switch of focus to the ‘very wet’ marsh surrounding the lake, where a sediment sampler was used to recover ~4 metres of lake deposits. These muds for the upper layers comprise peat and organic lake mud, but quickly give way to blue-grey gritty silts lain down as this last glacier declined and vanished 11,500 years ago.

Physical Geography and Geology interwoven and combined with fantastic weather, great views and some of the finest scenery in the UK; is there a better way to start your degree?

Faerie stories from the Lake District: the MSc field week October 2012

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The cast list

Prince Charming, Pinocchio, Lost Boy 1 – Richard Chiverrell

Alice in Wonderland, Lost Boy 2 – Dan Schillereff

The Pied Piper, Lost Boy 3 – Neil Macdonald

Overdramatic Damsel in Distress- Laura Crossley

Other Damsels in Distress- Huan Chang and Mary Oni

Sleeping Beauty- Amber Lewis-Bolton

Group 1 – Mary Oni, Kirsten Booth, Richard Walton, Ann Connor

Group 2 – Amber Lewis-Bolton, Matt Williams

Group 3 – Huan Chang, Laura Crossley, Danielle Alderson

Our story begins….. once upon a time (last week), in a land not so far away (the Lake District), the 2012-2013 Masters class in the School of Environmental Sciences set off in a convoy for the annual field class.

For those not inducted into the magical world of physical geography, a true physical geography field trip involves mud… and lots of it! The first day at Hawes Water did not disappoint with ‘competitive coring’ at the margins of the lake. Unfortunately, as we discovered, a competition cannot occur if one team loses their most valuable piece of equipment (a Russian corer stuck 1.3m below the water surface). A valiant rescue attempt was made by ‘Prince Charming’, but regrettably it was not meant to be. Although this was not exactly the ideal start to the field trip, this did provide the moment of the week in our opinion, after he stripped to the waist and submerged into the murky depths to rescue his beloved corer. Evidence is available; but, if required, it is pay-per-view, as poor masters students have to earn a (dis)honest crust somehow. Trust us, it is truly worth it!

Day 2 involved a trip to Roudsea Wood and the coring of an ombrotrophic peat bog. Key discoveries included how to meticulously classify sections of peat cores, and the pattern of changes in bog surface wetness and climate over the past 3000 years. Also important was the parallel invention of a game based on the US version of the sport ‘rounders’, this used corer rods and balls of intertidal clay and is perhaps one for future students to develop. A full scale mud fight was avoided, despite subtle prompting.

Biggar Marsh was the destination for day 3; a salt marsh near Barrow on Walney Island. The aim was use short cores and the record of radionuclide deposition across the salt marsh to discover the controls over the spatial pattern of sediment deposition. A visit from law enforcement officers and the National Coastguard proved the highlight of the day, after local residents believed children may have wandered into the tidal marsh – we were armed with differential kinetic GPS and gamma spectrometers so clearly youngsters in Barrow have expensive toys! The ‘Prince’ managed to charm his way out of any altercation with the law. After a short field day, magnetic susceptibility, XRF and radionuclide measurements were completed back at Castle Head in our makeshift laboratory through which we discovered evidence of peak radionuclide discharge from Sellafield.

Day 4 involved work at Brotherswater, a beautiful lake patrolled by some rather sinister and hungry swans. We used Russian and Gravity corers to take sediment cores from the lake bed from our leader’s vessel. This heavy work was a team effort as the water was 15m deep. We recovered 3m of brown laminated mud and two gravity cores. The now tired motley crew were able to take a well earned break, whilst the ‘The Lost Boys’ abandoned them to recover materials from sediment traps. Three ‘damsels in distress’ were stranded on the vessel as the circling swans moved closer and closer and the others marooned in a slightly safer location at the mouth of the raging Dovedale Beck. Further games ensued, ‘underwater golf’ a game played with a river, a metal pole and a golf ball*. Eventually we were rescued and further cores were retrieved from the lake bed, and treasures of the day were conveyed at a sedate pace to Castle Head for the application of a wide range of techniques (environmental magnetism, geochemistry and pollen analysis) which allowed us to open a window to view the environmental processes of the past 500 years.

Day 5 involved further work at Brotherswater where we recovered more sediment and followed ‘The Pied Piper’ to an eerie, probably haunted, abandoned mine to look for further treasure: lead, silver and zinc. Exhausted and overflowing with knowledge about monks, farming and tree felling. There was an obligatory visit to yonder hostelry, the excellent Brotherswater Inn, to warm up, drink hot chocolate, eat cake, and mentally prepare for Neil’s driving over Kirkstone Pass to get back to the field centre. Possibly the best moment of the Brotherswater days was the look on Dan Schillereff’s face when the cores were unveiled; Alice in Wonderland comes to mind.

We loved Brotherswater, and all decided to return for days 6-7, the group projects. The catchment has a history of lead mining extending back 300 years and the three groups explored the evidence for this and other human impacts on the landscape in various sedimentary records. The first group used a portable XRF gun in the catchment and recorded the geochemistry of surface soils progressing 2km down the valley across former mining areas, current and former river beds, floodplains and agricultural fields towards the lake. The second with some trepidation entered the flooded impenetrable willow and reed swamps fringing the lake delta to explore how the river inflow had behaved over thousands of years. The third braved the vessel once again to take more cores from an alternative backwater location to explore any differences in sedimentation rate. Many hours of laboratory analysis followed and after processing the results, Friday evening culminating with group presentations of our discoveries. The education tables were then turned over as Neil Macdonald gained an education in recent music. Saturday concluded our trip and after extracting a slightly bedraggled ‘Sleeping Beauty’ out of bed, we began our trip on the long and winding road back to Liverpool.

We had a lot of fun on this trip, but we also worked very hard – field work all day and laboratory analysis during the evenings. Despite ‘Pinocchio’ telling us that we would have an early finish every night, this never actually happened, apparently that depends on your definition of early and time is relative anyway. We experienced a range of new techniques on this field trip which will support us in our further study. And as for the ‘happily ever after’ ending, that instalment we must leave for dissertation time in the summer.

THE END…. (or is it).

* Heath and safety: with underwater golf only the ball is submerged not the players, unless appropriate breathing apparatus is available. Life jackets should be worn.

Why we investigate lake sediment archives: Some personal perspectives

Post by Dan Schillereff

Puzzled faces are often returned when people learn that my doctoral research involves analysing mud extracted from the bottom of a lake. Common questions include why? How? What does it look like? My interest in lake sediments was developed through my Undergraduate degree at Liverpool and addressing these queries is now an important part of my PhD. In this post I will briefly outline some answers from a personal perspective.

Why? Lake sediment records have contributed hugely to our understanding of past environmental changes around the globe. Where a lake is fed by a river which drains the local catchment, sediment is transported through the fluvial system and deposited at the lake bottom. These sediments can be characterised using numerous parameters measured in the field or using advanced laboratory techniques and fluctuations in these measurements may indicate a change in local climate, land-use or vegetation cover. My research focuses on recovering sediment sequences from lakes in the English Lake District (Bassenthwaite and Brotherswater) which should contain records of extreme flood events which have occurred in the catchment in the past. If the sedimentological signature of discrete flood layers within a long sediment sequence can be deciphered, counting the number of such layers can provide insight into flood frequency and a relationship between grain size and river discharge may provide data on flood magnitude. Our sediment cores cover many centuries and, in some cases, millennia. These datasets will therefore be invaluable to river managers and policy makers who need a better context in which to place the current spate of extreme flood disasters witnessed in recent years and to develop more effective mitigation scenarios of future flood risk.

Coring for lake sediment

How? Many techniques have been developed to extract the soft sediments lying at a lake bottom. Preserving the internal structure of the sediment sequence is crucial, however the high water content of the mud means methods must be used which recover the lake sediments with minimal disturbance. For extracting sequences potentially many meters thick, we use a Russian-style sediment corer, which consists of a semi-cylindrical metal case with a rotating cover plate, with an optional manual hammer system that can be employed. At Liverpool, we have constructed a raft which enables coring to take place on a solid, well-anchored platform. The corer is lowered through the water column, with metal support rods attached as required to reach the desired depth. If the sediment proves difficult to penetrate, the hammer system is attached to the vertical supporting rods and a weight is lifted and dropped to drive the corer further into the basal sediments. When the desired depth is reached, the support rods are rotated clockwise, the cover carves through the sediment column and an undisturbed sediment sequence is captured within the casing. The corer is lifted to the surface, lain flat and the rotating motion is reversed, revealing a lovely stratigraphic sequence upon the cover. Each core drive (which can be 0.5, 1.0 or 1.5 m in length) is encased in PVC drainpipe and transported to the lab here in Geography.

Lake sediment core

What does it look like? In my short academic career, I have observed numerous textures, colours and smells associated with mud extracted from different lake environments. Examining the factors which generate such characteristics is far beyond the scope of a blog post, but certainly these are subjects which feature prominently in the Physical Geography Undergraduate curriculum and the MSc Environment and Climate Change course.