December fieldwork

Because we've been busy with the project dissemination, during December we've only made one topographic survey. On December 28th we've repeated the 24 topographic profiles to have a reference situation in case storm waves occur.

No overwash occurred during the last high-tides, but probably during December there were overwash events in some parts of Barreta Island.

Shell debris alignments consistent with overwash.

Aeolian rework of the barrier surface is visible in many areas, either by ripples, lag surfaces or depositions behind obstacles on the surface. Some vegetation is covered by this process.

Aeolian ripples and aeolian sand accumulation.

The lagoon margin is varied along Barreta Island. In places, a tidal flat exists, while in others there is a sandy beach adjacent to the tidal channel.

Tidal flat at the backbarrier.

During this survey, barrier erosion was noticed on the lagoon beach, which is likely related to changes in the inner channel currents.

Erosion bluff on top of the lagoon beach.

Dissemination of the project

First results of RUSH project were presented on the 7th Symposium on the Atlantic Iberian Margin (MIA 2012), in Lisbon.

For more information about the conference click here.

The communication details are:
Matias, A., Carrasco, A.R., Pacheco, A., Loureiro, C., Nunes, M., Ferreira, Ó., Armaroli, C., Masselink, G. (2012). Do espraio ao galgamento: uma perspetiva integrada. 7th Simposium on the Atlantic Iberian Margin, Lisbon, Portugal, pp. 30.

Another abstract was accepted for the 8th IAG International Conference on Geomorphology, August 27th to 31st, 2013, in Paris. 

For more information about the conference click here.

The communication detais are:

Matias, A., Carrasco, A.R., Pacheco, A., Loureiro, C., Nunes, M., Ferreira, Ó., Armaroli, C., Masselink, G. (accepted). Longshore variation of overwash occurrence in a barrier Island (Portugal). 8^th IAG International Conference on Geomorphology. Paris, France.

pre- and post-overwash in November 2012

In November we were able to do what we've been trying for the 3D fieldwork: a good timing on pre- and post-overwash surveys.

We've made a survey on November 14th and 19th, and the waves increased between November 15th and 17th. During this period, the significant wave heigth was more than 3.0 m (threshold for storm occurrence) and the tidal level reached 1.6 m above Mean Sea Level.

Average  wave period (blue) and maximum period (red) between 11 and 18 November, 2012.

Overwash occured in many sites of Barreta Island, and in places the water intrusion reached the lagoon water, on the backbarrier side of the island.
We noticed that some features are crucial for the occurrence (or not) of overwash. The swash bars of Ancão Inlet seam to play a role.

Ancão Inlet ebb delta.

Aahhhh, and during the bathymetric survey we were visited by a group of dolphis. Here's a photo to prove it. They're really hard to photograph!!!

Glimpse of a dolphin's fin.

Team:
14/11/2012: Ana, Rita, Carlos, Sílvia.
19/11/2012: Ana, André, Mara

skipper: Zapa