WORKS CARRIED OUT:

1.- 07:45 hrs. Arrival to the area, use of EPIs by all the personnel on board and gas gauge verification by the IGN team, with the aim to check the presence of possible harmful substances in non-tolerable levels. It is verified that the levels of gases are not outside the tolerance and recommended levels, hence the vessel enters the phenomenon area to begin the planned work.

 2.-09:20 hrs. Hydrological sampling with a multiparametric device at the 27º 40.2 N - 018º 03.3 W position to a depth of 415 meters, that was used as a "blank" (area aparently not influenced by the phenomenon) at a first approximation to determine the general characteristics at biogeochemical level (temperature, salinity, pH, chlorophyll, turbidity, dissolved oxygen, gases and nutrients). In parallel, surface samples were taken to analyse the mentioned parameters a posteriori.

3.- 10:10 hrs. Hydrological sampling with a multiparametric device at position 27º 37.1 N - 018º 00.6 W until 150 meters deep to determine at a first approximation the general characteristics at biogeochemical level (temperature, salinity, pH, chlorophyll, turbidity, dissolved oxygen, gases and nutrients) inside the patch generated by the phenomenon. In parallel, surface samples were taken to analyse the mentioned parameters a posteriori.

 4.- Collection of biological solids samples (clearly benthonic species) that were significantly found in the interphase water, that visually seemed "clean" and "non-affected" by the phenomenon.

5.- 11:15 hrs. Starting of a new sampling station in the area affected by the phenomenon by means of a multiparametric probe; however, an emergency communication received on board requires the ship to end the work and carry out the ¡nmediate evacuation of the area. This is due to the existing risk after sighting fuming pyroclasts at short distance from where the RV Prof. Ignacio Lozano was positioned.

 After the warning, and in view of the risk level and the bad sea state conditions, the vessel's captain decides for security reasons to return to La Estaca harbour coming back by the west side of the island, which delayed the vessel arrival until yesterday at 18:00 UTC due to the greater cruising distance .

 Upon arrival to the harbour, the first analyses of the obtained data were carried out, aiming to make available the preliminary informations possibly before the day ended.

 Two preliminary graphs are included, which correspond to the vertical distribution of pH and turbidity measured in the two aforementioned stations that were sampled.

 These two parameters have characteristic values with small variations on absolute values in the archipelago waters and in this area around The Hierro Island, and are directly affected by the volcanic activity.

 The pH diminution and the increase of turbidity found in the sampled stations are of great magnitude and clearly point out the effect of the volcanic effect in the area.

 Graphs show that in the zone of the surface patch there are two layers affected, one on the surface and another centered at 110 meters of depth; however in the other station where a surface patch was not seen, a layer located at about 80m of depth appears too.

The data are being currently calibrated, analysed and validated and therefore should be considered absolutely preliminary and published solely to the effects of early information.