Expedition Name (& Club): Tresviso 2022 (BPC, SWCC, Cardiff Hill Divers, CDG)

Destination country: Spain
Region: Eastern Massif, Picos de Europa, Northern Spain.

Lat: 43.2587 Long: -4.6699 Elevation: 2100 m
MEF funding: none

Leader: Mr. Phil Walker

Brief Expedition objectives:

List a short summary of the main Expedition objectives.

The 2022 expedition will continue with the long term objectives of the project, in particular there will once more be 1 team based in Tresviso, concentrating on the Cueva del Nacimiento and Cueva de la Marniosa systems
Main objectives for Nacimiento are: a draughting lead at end of Jurassic World and the Bastard’s Ramp, both discovered in 2021 in the very furtherest reaches of the system. A long term resurvey project of Nacimiento will be started

Main objectives for Marniosa are: Ddive beyond Sump 2, exploring ongoing stream passage at the bottom of an undescended P6. Several significant avens to be climbed.

1 team will also be based in Vegas de Andara diving the terminal sump of Sistema Sara (-593m). This is major project and will require re-exploration / re-rigging of the entire cave. The ideal is to be able to dive the sump on this trip, but numbers and knowledge of the system might mean that 2022 will serve as a preparation trip for an attempt on the sump in 2023.

How can the GPF support your Expedition?:

Please explain the aspects of the trip which make it eligible for Ghar Parau funding.

All grant aid will most likely be used to support the diving objective in "Sistema Sara". Existing group equipment will be provided but the deep and wet nature of "Sara" will require more resources than currently in the store and the exploration will need to be largely self sufficient from the main group in Tresviso as the "Sara" objective requires 4x4 access and camping on the Andara plateau. The majority of aid will be used for extra rope and metalwork and potentially used for costs for generator purchase / hire

Detailed description of objectives:

Give a more detailed account of the purpose of the trip, including any particular known caves you intend to visit, specific areas where you will explore for new cave, and scientific experiments you will attempt.

In an area as complex as this, it makes more sense to discuss the general aims of the project, rather than individual projects, digs, and passages. Here we will discuss the 4 main areas targeted by current exploration:

1. Cueva del Nacimiento - Exploration at the far end. In 2021 the previous limit to exploration (a small sandy choke) was dug out and passed to circa 300m of new passage. This ends in another draughting hole, that requires digging. This is the highest and furthest point in the cave and most likely the ongoing continuation of the cave deeper into the mountain. Also at the far end of the cave, but down at the water level, a steep ramp was climbed to ~ 100m above on of the largest chambers in the system and continues upwards. These will both be revisited. These 2 major leads require 3-4 day camps at the far end of the cave on a rotation basis amongst the team.

2. Cueva de la Marniosa - Upstream Marniosa is >2km of windy, rift like streamway, that in 2018 was connected to surface pots coming in at the head of the main valley. Although this is in the opposite direction to a connection with Nacimiento, the passage here may be key to connecting to the deep potholes coming in from the Andara plateau. A large chamber (Alien Weaponry) was found in 2019 part way along the streamway, and some large avens enter this chamber. A camp in the chamber and a series of aid climbs against these avens will be attempted.

3. Sistema Sara - There is also an ambitious plan to dive the final sump in Sara, by all reports the largest streamway of any of the alpine pots in Andara and a high contender for the main drain of the region. The only stumbling block being that it has not been visited in nearly 30 years. This will most likely require total re-rigging of the cave and re-exploration / route finding, so it may become more of a preparation trip for an attempt in 2023. A dye trace of Sara will also be attempted.

4. Cueva de la Marniosa - Downstream Marniosa leads to Sump 1. This was passed in the 80's to Sump 2. Sump 2 was finally passed on the 2017 expedition and was left ongoing at a P6 down into continuing streamway. In 2019 a dye trace confirmed this water reappears in the Nacimiento upstream sump. The completely different size and scales of passage / water between the two sites suggests something else in between the two (i.e. intersection of major underwater trunk passage). An attempt to push further into the streamway, will be attempted by a team of divers (this objective may be dropped, depending on progress of objective 3)

Alongside the exploration of new passage, one of the overarching aims of the Tresviso Caves Project is to collate and document the area, providing an online database for all the caves in the region. To date 79kms of cave across 1095 sites have been described, logged and made publicly available along with relevant surveys, descriptions and possible leads.

Previous work in this area:

Give details of any previous work in this area by your own and other teams. Include references to reports and articles published on the area, and the names of any local cavers or academics with whom you have discussed the Expedition.

Under the banner of the Tresviso Caves Project, all available reports to the area have been filed, documented and converted into modern formats, with many leads highlighted and key surveys redrawn and updated in Therion.

The key reports have been uploaded online and can be found at http://www.tresvisocaves.info/publications/ and a a full bibliography of publications can be found here: http://www.tresvisocaves.info/bibliography/