Yunnan 2004 Expedition Prospectus



Following on from work in 2003, the Hong Meigui Yunnan 2004 expedition aims to find and explore caves with up to 2,300m depth potential in the mountains of Zhongdian, Yunnan Province, China.

Northwest Yunnan province, showing Zhongdian and the Yangtze (Chang Jiang). Roads are red. Pink is high.

Yunnan province is located in southwest China. It shares borders with Vietnam (to the south), Burma (to the west), Tibet and Sichuan (to the north), and Guizhou and Guangxi (to the east). The expedition's focus is in the north of the province. Here, the close parallel valleys of the Nu Jiang (Salween river), Lancang Jiang (Mekong river) and Jinsha Jiang (Yangtze river) run north-south, cutting deep gorges between mountain ranges whose summits are typically 4000m and higher. This provides the steep relief that is (among numerous other factors) conducive to deep cave formation, and that partially underpins our high hopes for realising the area's cave depth potential.

The expedition area. Caves, previous camp locations and (some) mountain access routes found during the 2003 expedition are marked.

The Yunnan 2004 expedition area lies in the mountain range that runs north-south between the valley containing the town of Zhongdian, and that of the Yangtze. Relief at the west edge of the plateau is extreme, with a drop of over 2,000 metres down to the Yangtze in a horizontal distance of 5-10km. (The drop to Zhongdian at the east edge is more gentle: a mere 800m drop for 5km horizontal.)

The expedition plateau comprises both Paleozoic (i.e. 543 to 248 million year old) and Mesozoic (248 to 65 million year old) rocks, which outcrop in a north-south band that is 20--40 km wide. The Mesozoic rocks are dominated by impermeable mudstones, but the Paleozoic sequence contains thick intervals of limestone. In many places limestone intervals been tilted so that their bedding is now nearly vertical.

The 2004 expedition is the fourth in a series. Attracted by the prospect of a virtually untouched limestone region with unprecedented depth potential (up to 4000m in the northwest of the province), Yunnan 2001 made contact with academics at the Geography Department of Yunnan University. Yunnan 2002 returned with 4 members for 9 weeks, carried out a thorough reconnaissance throughout the north of the province, and narrowed the project's focus to the area of greatest promise: a mountain range lying west of the town of Zhongdian. Yunnan 2003, a nine-person expedition over five weeks, focussed exclusively on that area, building up a comprehensive understanding of its geology, access routes and local infrastructure, and logged and began exploration of some 80 cave entrances. Each of these expeditions shares a high proportion of its membership with the present expedition.

Three years in, the Yunnan project enjoys a strong working relationship with the geographers at Yunnan University. In 2003, two academics, Liu Hong and Huang Chuxing, joined our expedition for part of its time in the field. We hope that more will join us, and for longer, in 2004.

Expedition Reports from the Yunnan 2002 and 2003 expeditions are available online:

  • Yunnan 2003 report
  • Yunnan 2002 report


    Primary aim: To find and explore deep caves in the Zhongdian mountains of Yunnan Province, China.


  • To continue exploration of C3-81. This stream cave, at 3900m altitude, lies about 15 km from the resurgence C3-1. Interestingly, the direction connecting the two locations approximates the general strike of the limestone bedding in this area. This may favour water flowing from C3-81 towards C3-1.
  • To explore logged caves around the Ye Kang area (Camp 11), and to search for additional entrances.
  • To return to the area surrounding C3-4 (a cave found and partially explored by the 2002 expedition) during yak farming season, and collect location information about other caves in the vicinity from local farming families.
  • To carry out a plateau crossing, north of the areas investigated to date. A long straight valley provides an ideal route, and passes across geological boundaries where caves are reported to be located.
  • To search for additional resurgences. C3-1 lies on a geological boundary, where limestone gives way to metamorphic (and some igneous) rocks. Searching elsewhere along this boundary may lead to the discovery of additional resurgences.
  • To search for and explore further high-altitude entrances, especially along geological boundaries and in geological blocks found in 2003 to contain many entrances.

    Secondary aim: If feasible, to carry out a dye trace experiment, from C3-81 to (a) C3-1, and (b) various locations in the Jinsha Jiang and its tributaries.

    Secondary aim: To produce an adventure film.

    Minor aims:

  • To assist the Yunnan University Department of Zoology, by collecting, preserving and submitting samples of high altitude cave life.
  • To encourage caving for sport and exploration among interested Chinese.

    Dye trace experiment


    Frequently, during a complex cave exploration project, information about the area's hydrology will be central in making exploration decisions. An exploration team needs to know the destination of water in each high-level cave, and the source of water issuing from each resurgence, in order to direct exploration effort to the locations most likely to lead to underground connections. From surface inspection and known geological information, however, underground water routes can usually only be badly guessed at.

    Water tracing is a technique used to investigate underground hydrology, and can provide this crucial missing information. A fluorescent dye, such as Sodium Fluorescein or Rhodamine WT is placed in an active stream, and its route traced by placing activated charcoal detector bags in underground streams and/or at possible resurgence locations. Any dye in the watercourse is adsorbed onto the activated charcoal and can later be extracted using an allutant. This qualitative method of water tracing, outlined in Smart and Friedrich 1982, allows connections between stream sinks and resurgences to be established, and can be relatively easily undertaken by cavers in expedition environments. Such experiments have been successfully carried out by expedition cavers in the Picos de Europa, establishing many connections between different cave systems, and from many of the caves to a resurgence more than 1000m below (Mead, Mead & Horsley, 1991).


    If feasible, we plan to carry out a dye trace, placing Rhodamine WT dye in the stream in C3-81. (C3-81 is a cave explored to 100m length in 2002, and left at an undescended pitch.) Rhodamine WT was designed specifically for water tracing, and can be detected in water at very low concentrations of 0.013 Ug/l in water (Smart and Laidlaw, 1977).

    Three charcoal detectors will be placed at each of the following locations:

  • inside the major resurgence cave (C3-1);
  • at the outlets of the two minor resurgences (C3-45 and C3-46);
  • at any other resurgences identified in the area during reconnaissance in January 2004.

    The detectors will be changed on a weekly basis. Dye will be injected in C3-81 in week 2 of the expedition, after one set of background samples have been collected from all resurgences.

    One of each set of three charcoal detectors will be analysed in the field by alluting the charcoal in a solution of 175ml Propanol, 95 ml distilled water, and 100 ml of 35% ammonium hydroxide. Strong positive traces will be visible to the naked eye; weaker positives will be visible when viewed under ultraviolet light. If no dye is detected in the first week, a larger quantity of dye will be injected into C3-81.

    If positive results are not obtained during the expedition, the duplicate detectors will be analysed at a laboratory in the UK, when the expedition returns. Once alluted, samples will be analysed on a spectrofluorometer or filter fluorometer, which enables lower concentrations of dye to be detected.

    To minimize the chances of false positive results, dye will be handled with care and those handling the detector bags will have no contact with the dye.


    Mead, U., M. Mead & D. Horsley (1991) In Proceedings of Oxford University Caving Club, Vol. 11.

    Smart, P.L. & H. Friedrich (1982) "An assessment of the methods and results of water tracing experiments in the Gulung Mulu national park, Sarawak". Transactions of the British Cave Research Association, Vol. 9, No. 2, pp 100-112.

    Smart, P.L. & I. M. S. Laidlaw (1977) "An evaluation of some fluorescent dyes for water tracing". Water Resources Research, Vol. 13, No. 1, pp 15-33.

    Adventure film production

    During the Yunnan 2004 expedition, Tim Guilford, assisted by Richard Gerrish, will make a film about the search for the world's deepest cave.


    There have been few successful films about cave exploration. This is partly because the cave environment is one of the most difficult on earth to film in using traditional techniques, and partly because it is in the nature of cave exploration that the outcome of each day is unpredictable. Yet, the descent of the world's deepest caves remains one of the last true exploration endeavours on our planet. Dr Guilford's own film-making exploits the fact that Digital Video equipment is now so compact, light-sensitive, and high quality that it can be used even for TV broadcast. He has developed a 'one-man' system of filming, lighting and sound recording that enables him to be present at the sharp end of exploration, filming events as they happen without the need for rehearsal. This approach avoids the single most debilitating factor in adventure film-making: lack of spontaneity. It is primarily the reactions and emotions of the people involved that make a compelling story. The aim will be to record events on the expedition, and during its planning and build-up, focussing intimately on the core characters, and on the action as they precipitate it. This combination will provide the 'living script' for the film, and will offer a unique window on nature of human aspiration at the same time as documenting live an example of an important phase in the history of earth's exploration.


    For underground action:

  • Sony PC8E (1CCD; DV format) with wide-angle lens attachment;
  • Sony CVXV1 Minicam (1CCD) for helmet-mounted and other 'on-board' shots (also useful for unobtrusive 'spy' shots of local people, or maintaining intimacy whilst filming sensitive social contexts such as arguments);
  • Sony compact powered directional external microphone (ECM-MS907);
  • Sony URX P1 light-weight radio-micropohnes for intimacy of caver soundtrack on pitches etc (diversity signal helps cope with obstructed cave environment);
  • 12V sealed lead-acid Yuwasa cells (good power output, robust, and readily available abroad);
  • 2 x Unisolar Smartcharge FLX-11Solar chargers with inverter system;
  • 4 x Custom-built 12v 50w Halogen dichroic lighting units;
  • 2 x Pelicase protector;
  • Sony sportshousing for aqueous passage or waterfall shots
  • 3 spare info-lithium batteries for both camcorders;
  • mini-tripod.

    For above-ground and easier-access underground work:

  • Sony DSR PDX10 (3CCD; DVCAM format). This provides better image quality for shots in less demanding circumstances, and where viewer expectations are higher and the lower quality of DV more visible;
  • fluid head tripod.

    Producers' credentials

    Tim Guilford is a cave explorer, photographer and filmmaker with 15 years exploration experience, including expeditions to Spain, New Zealand and Uzbekistan. In the UK, he has personally discovered over 15km of virgin cave passage. He is two-time winner of the British Cave Research Association (BCRA) national Premiere Trophy for still photography, and two-time solo winner of the BCRA national Film Salon (2001, 2003). Recently, his cave exploration film Caught Between A Rock And A Hard Place (co-produced with Justine Curgenven and Kate Snell) was declared winner of the 2003 BANFF Mountain Film Festival "Best film on mountain sports" category, and two of his caving films have been accepted by National Geographic Channel International.

    Richard Gerrish is a cave explorer with 9 years sport and exploration experience. He has participated in expeditions to France, Spain, Austria and Mexico, and was a member of the Yunnan 2002 and 2003 expeditions (in the latter case serving as Deputy Expedition Leader). He was the sole director and cameraman for a one-hour documentary film covering the Yunnan 2003 expedition, which is currently under production in association with Creative Touch Films Ltd.


    Personal travel

    Travel to base camp typically begins with an international flight to either Hong Kong or Kunming. From Hong Kong, one can reach Kunming by crossing the border to Shenzen in mainland China, and taking a domestic flight. Sleeper buses between Kunming and Zhongdian run several times nightly, and take approximately 10 hours.

    Individual expedition members will be responsible for arranging their own transport to Zhongdian.

    Local transport between base camp and the mountains will be by local bus, hitchhike or chartered minivan.

    Equipment transport

    Where possible, equipment from the UK will be carried to China with expedition members. Additional equipment will, if necessary, be shipped to our Field Agent in Kunming, and collected en route to Zhongdian at the start of expedition.

    Equipment already owned by the Hong Meigui CES, and stored in China, will be collected from the Society's headquarters in Guilin (Guangxi province) by an advance party.

    In the mountains, equipment will be carried by expedition members and by hired horses/yaks.

    Food and accommodation

    The expedition will set up a base camp at the Milk River Guesthouse, a Tibetan-run guesthouse in the north of the town. This was used as base by the Yunnan 2002 and 2003 expeditions, and we have a friendly relationship with the guesthouse owners.

    In the mountains, accommodation will be in lightweight two-man tents.

    Cheap food is abundantly available from street cafeterias in Zhongdian. In the mountains, the expedition will cook on petrol stoves.

    Callout system

    Cavers will usually work in small groups of two or three. This is the maximum team size that can usually be useful on a single underground trip, and larger teams would run higher risks of hypothermia due to the forced inactivity of some members at any time. In addition, this small team size makes for an efficient expedition, as manpower divides to explore many caves simultaneously.

    The downside of working in such small teams, of course, is that there is less help available in the unlikely, but ever possible, event of a mishap. The expedition will run the standard 'callout system', which is aimed at delivering timely help in the event of an underground or surface incident, without an alarm message having been relayed back to base. Teams leaving camp record the following details in the expedition logbook: (i) number and identities of team members, (ii) trip destination (i.e. cave index number(s) and/or intended locations of surface work), (iii) planned activities and route, (iv) estimated time of return to camp, (v) 'callout time'. If the team fails to return to camp by their stated callout time, a search and rescue operation is promptly initiated.


    Insurance will be arranged on an individual basis. (Past experience indicates that this works out cheaper than insuring a cave expedition on a group basis.)

    The insurance status of participation in cave expeditions is currently unclear. There are specific reasons for genuine concern over whether the policies that are usually used to cover such expeditions - i.e. "sport"/"adventure"/"travel" policies, including that negotiated by the BCRA specifically for the purpose of cave exploration - genuinely cover the possible accident scenarios we are forced to consider. We are currently consulting with the BCRA and with insurance companies, so that the situation can be clarified in time for expedition members to make informed decisions regarding their insurance cover for this expedition.


    The expedition's membership will include one professional doctor, and five explorers trained in expedition first aid. Medical equipment will include antibiotics and other prescription drugs deemed useful in the context of this expedition, at the discretion of the Medical Officer.

    Recording of entrance locations

    Entrance locations will be added to the database created over the past three years' expeditions, with WGS84 positions given directly by handheld GPS receivers and recorded as UTM coordinates.

    If the sky view is insufficient to receive a good GPS signal, the location of a nearby reference point will be recorded, together with the compass bearing and distance from the reference point to the cave. When even this is not possible (for example, in thick and spatially extensive forest), locations will be recorded by as many as possible of the following methods: triangulation from obvious landmarks, altitude (determined by handheld altimeter), written description of cave environs, entrance location relative to reidentifiable points in the vicinity.

    Cave surveying

    Significant caves explored by the expedition will be surveyed to the highest reasonable standard. In the majority of cases, this means surveying to British Cave Research Association Grade 5b.


    Still photography will be used to capture the range of expedition activities.


    The expedition will be equipped with mobile telephones (one phone per 2 members). These have a dual role: to enable small teams to keep in touch with one another via SMS, and to facilitate the coordination of a rescue in the event of an emergency. (Mobile telephone coverage is available at several points on the plateau, although not everywhere.)

    Collaboration with host country

    Yunnan 2004 enjoys a strong and productive relationship with academics at the Yunnan University Department of Geography. Two geologists joined us in the field during the Yunnan 2003 expedition; it is possible that a larger group will join us in 2004. Copies of all cave location and survey data, together with the full Expedition Report, will be given to the Department of Geography.

    Permission and permits

    Travel in China requires a tourist visa. This is obtainable in the UK from the Chinese Embassy in London, or Consulate in Manchester, for a UKP30 fee. No further official permission is required for this expedition.

    Timing and project completion date

    The expedition will spend five weeks in the field, from July 12 to August 23 2004.

    Dye trace results will be analysed on return to the UK.

    The expedition will publish an Initial Report immediately upon return, and a Final Report by December 31, 2004.

    Publication of results

    The Final Report will serve as the permanent record of the expedition. This will be a stand-alone publication. Hard copies will be distributed free of charge to grant bodies, sponsors, selected libraries and expedition members. The report will be made available electronically (free of charge) via the expedition's website.

    Risk assessment


    Risk: Illness (general)
    Measures:: Complete appropriate vaccinations, according to medical advice. Take appropriate hygiene precautions. Avoid dubious food. In towns, all drinking water must be bottled or boiled. On the mountain, all drinking water from a suspicious source must be boiled, or strained and treated with iodine.

    Risk: Road accidents
    Measures:: No reasonable measures possible.

    Risk: Robbery
    Measures:: Don't carry more cash than necessary. Don't argue in case of attack. (Robbery is estimated as unlikely, based on current UK government travel advice.)


    General measures to mitigate risks: Carry appropriate survival gear and first aid kit at all times while walking in mountains. Adhere to callout system (see 'Logistics').

    Risk: Injury
    Measures:: Use appropriate techniques, particularly when climbing or scrambling. Take appropriate precautions when cooking. Beware of yaks.

    Risk: Altitude sickness
    Measures:: Acclimatise according to current mountaineering recommendations. All expedition members to be educated in signs, symptoms and treatment of altitude illness (AMS, HAPE, HACE).

    Risk: Exposure
    Measures:: Carry appropriate clothing and survival gear at all times while walking in mountains. All expedition members to be educated in signs, symptoms and treatment of exposure.

    Risk: Sunburn/sunstroke.
    Measures:: Wear appropriate clothing and headgear. Use sunscreen.

    Risk: Getting lost
    Measures:: Carry map, compass and GPS where possible.

    Risk: Landslides
    Measures:: Avoid known hazard zones, as far as it is reasonable to do so.


    General measures to mitigate risks: Carry survival bags and first aid kit on all underground trips. Adhere to callout system (see 'Logistics').

    Risk: Rockfall
    Measures:: Remove any loose rock from the top of each pitch during original exploration. Exercise extreme caution when exploring boulderchokes, or other areas where the danger of rockfall is higher than usual. Be prepared to halt exploration if excessive objective danger cannot be removed.

    Risk: Vertical equipment failure
    Measures:: Ensure that all personal protective equipment is in good condition; discard and replace if in doubt. Rig pitches to avoid rub points.

    Risk: Falling
    Measures:: Exercise caution when caving. Use appropriate self-protection techniques. (All expedition members are experienced vertical cavers, skilled in the use of such techniques.)

    Risk: Exposure
    Measures:: as for surface.

    Risk: Getting lost
    Measures:: Trips to include cavers who know the route, where possible. Difficult route-finding areas to be way-marked.

    Risk: Flooding
    Measures:: Avoid trips in active caves on wet days. Get to know the way the caves react to water. Rig pitches to avoid water.