THE NEWBERRY CRATER LAKES, OREGON

What: The two Newberry Crater lakes are located at ~ 2 km elevation inside the Newberry Volcanic Monument area, which is located behind the Cascadian arc in the OR high desert, ~30 km south of Bend, OR. The lake waters are carbonate-rich, with neutral to slightly alkaline pH. Both lakes have subaqueous inputs of volcanic fluids: East Lake mainly H₂S and CO₂ with mercury as a pollutant, and Paulina Lake mainly carbonate-rich fluids with abundant Fe, As, Si and P. Both lakes have diatoms as important autotrophs, and the lake ecosystems are almost completely based on components from inside the earth: CO₂, Si, and P are all of geothermal origin, whereas only the fixed nitrogen is generated inside the lakes by golfball-sized Nostoc cyanobacterial colonies using atmospheric nitrogen. Just add sunshine and there is your ecosystem!

When & Where:  June 24-July 22, 2015.  Arrival in Portland OR on the afternoon of June 24^th. Stay in Newberry from June 25 to July 8, then drive to a college or museum in OR (location to be determined) and stay there from July 9 to July 21. Return to Portland OR on the morning of July 22 for return flight home. If someone from a nearby school joins this project (e.g., Whitman College), you may want to drive to Newberry and have your own transportation available. We can discuss the details about expenses in person.

Who:  Professor Johan (Joop) C. Varekamp (Wesleyan University, E&ES, Middletown CT) is a geochemist by training and has worked on volcanic lakes around the world for several decades. He has worked on these two lakes for three years. He will guide the fieldwork, the coring efforts, the water sampling, the CO₂ flux mapping, and the survey of the flood apron. Dr Greg Mulder (Lynn Benton) may join us with his team of engineering students to work with the subaqueous rover. Scott Herman, Wesleyan University alumnus, with a Master of Science degree from UC Santa Barbara and an independent geothermal consultant based in OR, may be recruited and help with the field work, camping arrangements, and boating. In addition, other help from Wesleyan Universty may be recruited as needed.

Project Overview & Goals:  Our research goals are to understand the current functioning of these two lakes (water budgets, organic productivity, magnitude of volcanic inputs) and their history over the last few 1000 years. We will sample the lake waters in vertical profiles and scan the bottoms of the two lakes for gas vents and hot springs, using a fancy depth finder / side-looking sonar set-up as well as mapping with suspended CTD probes (lots of kayaking!). We will try to sample the gases and hot fluids with a subaqueous rover (in collaboration with Lynn Benton College, OR), which also has a drill, grabber, and video recording equipment. Elemental mass balance studies for the two lakes are the ultimate goals, using measured and calculated water and element fluxes, organic extraction of Si-C-P-N, and measurements of CO₂ fluxes from the lake surfaces. We will collect cores of several m length to reconstruct the variations in volcanic gas input over time, apply tephrachronology to get ages, together with ²¹⁰Pb-¹³⁷Cs studies of the young sediments. After sampling and field data collection, waters and cores will be analyzed for their elemental and isotopic compositions, including d¹⁸O and dD in water, d¹³C in CO₂ and in dissolved carbon, and d¹³C and d¹⁵N in organic matter. The cores will be analyzed for major and trace elements by XRF and ICP-MS. I can set up a diatom project for someone interested in diatom identification in the cores and water-filter samples. In Paulina Lake, we also find ostracods, which can be studied and analyzed for d¹⁸O for paleo-hydrology work.

Potential Student Projects:

The volcanic inputs into these two lake systems and their variation over time. Sampling of lake waters and hot springs for water analyses (chemistry and stable isotopes); inferences can then be made on water residence times, mineral saturation, and toxic element dynamics. Sonar studies have shown bubble trains of gases that rise from the bottom of EL, but never reach the surface of the lake because they dissolve along the way.

The lake ecosystems. We have labeled this subproject ‘Proterozoic Park’ because cyanobacteria were already known in the Precambrian, and life in these lakes may mimic that of the far terrestrial past. Questions include what has happened to the ecosystem since the first introduction of fish in both lakes around ~ 1912. The only fossils apart from diatom frustules and pollen in the sediment cores are valves of ostracods in PL, which waters are close to calcite saturation. The waters of EL have very large and several m thick floating islands of (largely) submerged aquatic vegetation, which also contribute to the organic carbon loading of the sediment (up to 8 % C(organic) in EL).

The CO₂ dynamics of East Lake. The CO₂ input into EL leads to an interesting sequence of bubble input, dissolution and diffusion of CO₂ upwards, with subsequent gaseous diffusional escape from the water surface into the air. Little or no atmospheric carbon invades the lake, and a flux of volcanic/geothermal CO₂ leaves the lake. We will measure the flux of CO₂ at the lake surface with a CO₂ accumulation chamber with a LICOR CO₂ detector. All needed equipment is available (float chamber, LICOR detector, gas pump, solar cells, ‘waterproof’ laptop) and on-site we will build a raft with all equipment, and take measurements at various locations on the two lakes. We may also use gold traps to collect and determine the Hg escape from East Lake. We will take small gas samples for the detection of methane and measurements of carbon isotope ratios in the escaping gases. The dynamics of bubble rise, expansion, and dissolution would make an interesting side project of a more theoretical and / or experimental nature.

The Newberry lakes as a US Lake Nyos equivalent? The Newberry lakes have a strong thermal stratification in summer and a frozen surface in winter. Most CO₂ escapes during the mixing events in fall and spring and through diffusion at the surface in the summer. The lakes may have been more poorly mixed during past times with a colder climate, and CO₂ may then have built up in the hypolimnion. A perturbance or climate change may then create a turnover with associated lake explosion, as occurred at Lake Nyos (Cameroon) in 1976. The outlet of Paulina Lake (Paulina Creek) has many horsehoe-shaped water falls that are much too large to have formed with the modest water flow of the modern stream. Where the canyon enters the floodplain of the Little Deschutes River, a large apron of poorly sorted material is found with many boulders coated with white carbonates: a catastrophic flood deposit! The common interpretation is dam failure with resulting floods, but we like to explore in how far a lake explosion (such as occurred at Lake Nyos) or a volcanic event may have created this megaflood.

Details of potential Student Projects:

I.  Mass balance of volcanic inputs at Paulina Lake (1 student)

1. Flow rate at Paulina Creek – flow meter-flow rate water
2. Water sampling at Paulina Creek – element fluxes
3. Water profiles in PL
4. Water T measurements on long lines – find hot spots
5. Sample subaqueous hot springs with rover or remotely with bottle.
6. Collect hot spring sediments with grabber
7. Collect lake margin hot spring waters
8. Analyze all water samples for major, trace and isotopic compositions
9. Create elemental and isotopic mass budgets through modeling

 II.  Carbon balance of East Lake (1 student)

1. Sample East Lake water profiles
2. Find bubble areas with side scan and/or rover
3. Collect water + gases from bubble areas
4. Collect water from hot springs near lake beaches
5. Measure CO₂ evasion rates at East Lake and Paulina Lake
6. Create a mass budget for carbon (mainly in East Lake): how much comes in, how much goes out through diffusion/escape, and how much is fixed by photosynthesis – using carbon abundances and stable carbon isotopes

III. Core studies from both lakes (2 students, one for each lake)

1. Takes cores in PL and EL (big job in lakes 60 and 90 m deep!!)
2. Subsample both cores after photography and description
3. Determine volcanic ash content, biogenic silica contents
4. Analyze for Hg and As (probably come to Wesleyan for these analyses)
5. Determine Organic Carbon contents
6. d¹³C- d¹⁵N in organic matter
7. subproject-ostracod analyses from PL (needs ostracod specialist at home institution)
8. subproject-diatom analyses from both lakes (needs fresh water diatom specialist at home institution)
9. subproject–Hg studies on water from EL (speciation, concentrations)
10. subproject-Arsenic in PL core sediment è speciation study
11. Explain the unusual core sediment chemistry through the volcanic inputs and describe processes responsible for fixing the Hg and As into the sediment. Possibly XRD work on minerals in the sediments (Vivianite has been found).

Other topics (the four projects above have priority)

 IV.  Flood apron of Paulina Creek

1. Map and sample the flood apron
2. Core wetlands along the Little Deschutes river to find the distal flood layer
3. Study the morphology of the waterfalls in Paulina Creek
4. Estimate water flow rates at maximum discharge rates from geomorphic parameters
5. Get carbon isotope values from boulder incrustations è info on lake water composition at the time of the megaflood
6. Date the event from carbon debris in the apron or from the wetland sequences

V.  Petrology of the ashes and cinders surrounding the lakes and one or two young cinder cones at the N end of the Volcanic Monument area (see Google earth map). This project will only go ahead if not enough students are recruited for the four projects listed above. This needs a petrology expert at the home institution to advise for a subsequent thesis study. Rock analyses by XRF and ICP-MS, petrography, and radiogenic isotope work. What is the nature of the Newberry volcano: extension of the Yellowstone plume/ Columbia River basalts or back-arc basalts related to the Cascades chain?

Working conditions & Student Expenses

The Newberry lakes have two commercial resorts and many Forest Service campgrounds. The nights are slightly cool (it is at 2 km elevation) and the days can be hot and sunny. Much time will be spent on the water, be it on the pontoon boats or in kayaks. You should be able to swim and have either boating experience or willingness to learn. These lakes are favorite fishing spots for tourists so there is a fair amount of boating and other folks around. Despite that, it is an area of pristine nature and grandeur as rarely seen, but only 2 hours by car from the major town of Bend, OR. There are small restaurants at East Lake and Paulina Resorts and we will alternate group cooking and outings to the resorts for dinner, or make a short expedition to the Lapine truck stop (nearest village) for food (EXCITING!). We will work with Park Research permits, but respect for nature and the environment is expected. If some or all of you want to spend some of your own money, you can rent a cabin for 4 people at about $150.-/night for four persons and we would supply the equivalent camping fees ($40.-/night for four) . The expected private costs per person then is $30.-/night for 14 nights. The second two weeks will be spent on a college campus and we will find housing there either in dorms or in simple hotel rooms. Cell phone coverage at the lakes is absent (20 minute drive to get coverage), but there is incidental WIFI available at the restaurants. Dangerous diseases do not occur here as far as I know; an occasional wildlife issue may occur, but this well-known outdoors tourist location is not in the middle of Tibet or something like that.

The project expenses are high through the boat and van rentals and shipping of equipment, and I request a food contribution of each student of $500.- for the four week long expedition. The Keck budget will provide your RT air travel, camping fees and subsequent stays, all the food, and all research-related costs, with a remainder of a $1000.- stipend for each student (out of the $1500 Keck original or formal stipend). The work pace will be steady and by times hard: once you are on the lake in a boat we better finish what we were planning to do that day, but nothing extreme or endurance-related is expected. Many of the older fishermen/tourists are on the lake at 6 AM and get back by 5 PM! We will sometimes work as a group on a single project and sometimes work in subgroups. Ease of working with others and a sense of field camaraderie would be good character traits. Being able to camp for two weeks and staying clean (there are showers – take lots of quarters!) and well-fed would be helpful as well. And if you can cook, you sure are in business!

East Lake resort: http://www.eastlakeresort.com/

Deschutes Forest Service: http://www.recreation.gov/camping/paulina-lake-campground/r/campgroundFees.do?contractCode=NRSO&parkId=72097

Course Requirements:  If you want to work on a geochemical topic, you must have taken a course in geochemistry and/or isotope geochemistry. The sediment chemistry studies also need geochemistry/isotope geochemistry and or mineralogy/petrology. The flood apron studies need someone with a geomorphic fascination (taken geomorphology and hydrology), whereas those opting for beasty studies (diatoms, ostracods) would need a (micro)paleontology or geobiology course. The petrology project needs a Min/Pet/Geochem type student. Everyone would profit from some insights into modeling through Excel or with a common computer code.

One undergraduate thesis has been done in 2012 on these lakes by Jared Lefkowitz (A Tale of Two Lakes: Hydrothermal Geochemistry of the Newberry Volcano, OR), who received High Honours for his work (available for download at the Wesleyan Scholar website: http://wesscholar.wesleyan.edu/ees_etd/)

Contact Information

Students interested in these projects, please contact me asap

Email: jvarekamp@wesleyan.edu

Tel: 860 685 2248

http://scholar.google.com/citations?user=g3hP-1EAAAAJ&hl=en

We can discuss your options and recruit a local advising expert at your college.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Petrology of the ashes and cinders surrounding the lakes and one or two young cinder cones at the N end of the Volcanic Monument area (see Google earth map). This project will only go ahead if not enough students are recruited for the four projects listed above. This needs a petrology expert at the home institution to advise for a subsequent thesis study. Rock analyses by XRF and ICP-MS, petrography, and radiogenic isotope work. What is the nature of the Newberry volcano: extension of the Yellowstone plume/ Columbia River basalts or back-arc basalts related to the Cascades chain?