Cassola casts doubt on reliability of Gozo tunnel geotechnical survey

Experts commissioned to carry out geotechnical investigations on the seabed between Malta and Gozo have questioned whether their findings alone can be used to give a go-ahead for the project, according to independent candidate Arnold Cassola.  

In a Facebook post on Sunday, Cassola, who said he was quoting from the report itself, said that the experts themselves “cautioned that their geological model is not be taken as something definitive and sure”.

“In fact, whilst insisting that theirs is only a preliminary study – and therefore that other studies are needed – the experts have pointed out that there are a number of limitations to their geological interpretation of the seismic (earthquake) reflection data,” Cassola wrote.

Reflection seismology explores the sub-surface structure of the seafloor by sending artificially generated acoustic waves into the seafloor, where the different structures and objects beneath the bottom reflect it back according to their physical properties.

Cassola said that the experts’ report pointed to four limitations of the investigation including:

• Differences in resolution of geophysical and sedimentological data
• Discontinuous seismic reflectors, likely due to the occurrence of fractures and cavities
• Limited stratigraphic information provided by only two offshore boreholes
• The occurrence of extensive wipe-out zones linked to the presence of gas within the sedimentary succession, which may be hiding in structures in some area

READ MORE: Fourth ferry ‘success’ must be factored in tunnel studies, Gozo workers say

“In view of these non-irrelevant limitations and also in view of the subjective nature of geological interpretation, the experts themselves have clearly stated that the geological model generated for the study commissioned by the Maltese government, conducted between 2016 and 2018, is characterised by a degree of uncertainty,” Cassola said.

He added that in view of the experts’ “frank admission” that their preliminary study “can’t guarantee the safety of the proposed sub-sea tunnel, both the government and Opposition should reconsider their position on the proposed link.

Cassola has insisted on a number of occasions, that all studies must be made public before any decision on the tunnel is taken. Similar calls have been made by the Nationalist Party, including one last week.

Back in April, a Transport Ministry spokesperson told MaltaToday that all geological studies related to the development of the Gozo tunnel would be passed on to the “relevant authorities” in the development permitting process, at which point they will be made available for public consultation.

That same month, both the government and Opposition voted in favour of a motion supporting the construction of a permanent link between the two islands.

A MaltaToday in June found that 60.9% of respondents favoured the project, down from 63.1% some seven months prior. A quarter of respondents said they were against the project with 12.5% declaring they were uncertain.

Despite enjoying the support of a majority of the population, the need for a tunnel has been questioned in recent weeks, given the dramatic reduction in ferry waiting time since the addition of a fourth ferry to the Gozo Channel’s fleet.

Last month, Transport Minister Ian Borg said that Infrastructure Malta was working according to established timeframes and would be issuing the first tenders for the project by the end of 2019.

Although environmental impact assessments are still to be completed, Infrastructure Malta has said it will be moving ahead with the first stage of the tendering process and will be asking business interested in planning, building, or operating the tunnel to come forward and register their interest.

READ MORE: Fourth ferry solves queues, but Gozo business still wants tunnel