Tsunami map man here for New Year

TSUNAMI EXPERT: Gisborne holds a special place in the heart of Jose Borrero, for family reasons and because he simply feels Tairawhiti is a special place. A passion for studying tsunamis was motivation to complete the recently-released tsunami inundation mapping report. He wanted to provide the best information possible to help in the formulation of evacuation plans now being developed by Civil Defence. He and son Carlos-Tui (6) are pictured at Waikanae Beach. Picture by Liam Clayton

Dr Jose Borrero is a director and senior consultant with eCoast Marine Consulting and Research, the company that worked with Niwa to compile a detailed new look at the region's vulnerability to tsunami.

He is a man with close family and personal ties to Gisborne and its coast line.

The report, which was peer-reviewed by GNS Science, paints a much grimmer picture of what would happen across Tairawhiti in the event of a major “tidal wave” event hitting this region.

Much of the Gisborne and Poverty Bay Flats area will be inundated “when, not if” a major earthquake happens along the Hikurangi subduction zone off the East Coast.

The report also illustrates the region's vulnerability to tsunami generated further away across the Pacific, with less sizeable, but still substantial, inundation zones involved.

It has been available for viewing on the council's website since mid-December.

Dr Borrero led the study and along with his collaborator Dr Cyprien Bosserelle at Niwa, prepared the report for Gisborne District Council.

He and partner Holly Thorpe, with their children Carlos-Tui (6) and Bella-Ana (3), have been staying with Holly's mum Kris in her beach-side home at Makorori.

“The Tairawhiti district has a big personal connection for me, and the family connections are deep too because the family live on the beach front at Makorori and Wainui.

“Holly's mum Kris (Thorpe) was very well versed in tsunami risk before I met her.

“So I was very interested in getting the Tairawhiti tsunami inundation project going.”

Jose, a keen surfer, said Gisborne was one of the first places he came to when he first visited New Zealand in 2003.

“I've been back here many times since. It's a special place.”

He said they looked at a variety of different earthquake scenarios and used state-of-the-art computer models to do the inundation mapping.

“We considered a worst-case scenario, to give Civil Defence the maximum credible event from which to make up evacuation plans for the district. The inundation extents predicted for Poverty Bay are similar to what happened in Sendai, Japan in 2011.

“I must point out that the inundation maps we produced were for an event at the lower end of probability.

“An 8.9 magnitude earthquake is an extremely rare event, but we cannot discount it happening.

“The big Japan quake and tsunami several years ago was a magnitude 9 and occurred on a subduction zone that had not previously produced anything that big.”

The report states an 8.9 magnitude quake here would be a once-in-2500-year event.

Dr Borrero said the report was certainly not about generating any kind of panic in the community.

“That was never the intent. Our aim was to provide information to help formulate evacuation plans, and knowledge is power.

“The prospect of a major quake and resulting tsunami is not something to live in fear of, but it's something people need to understand.

“One of the reasons why I did this work is that every family should have a plan of action, particularly if they live in the high-risk areas shown in the mapping.

“For example, have you thought about your evacuation route? Have you discussed it with your family? If an earthquake happens at night, do you know where the flashlights are? Little things like this can make a difference.

“I've seen first-hand the difference an evacuation plan can make. In Indonesia, for example, there were two villages close to each other, one had set up an evacuation plan while the other hadn't. In the village that did, everyone survived despite every house being swept away. In the other village, nearly everyone was killed.”

He also said people needed to be aware of the natural warning signs of an impending tsunami.

“Like an extremely strong or long-duration earthquake — that's certainly one of the warning signs.”

Dr Borrero earned a PhD in coastal engineering in 2002 at the University of Southern California (USC) in Los Angeles.

After a stint in the academic world, he moved to Raglan in 2006 to work in consulting. In 2012, Jose and his partners started eCoast, a Raglan-based marine consulting and research company which focuses on providing environmental, engineering and advanced computer modelling expertise worldwide.

Jose has been studying the causes and effects of tsunamis since the mid 1990s. Over this time he has documented first-hand the effects of tsunami in places such as Mexico, Central America, Indonesia, Papua New Guinea, Turkey, Marquesas Islands, Samoa and Peru.

In the early 2000s he produced tsunami inundation maps for the State of California, establishing methods for assessing tsunami hazards which were applied directly to the Gisborne District study. During his time at eCoast, Dr Borrero has also prepared tsunami hazard reports for the Waikato, Bay of Plenty and Northland regions of New Zealand.

“It has been great to work with the Gisborne council” adds Dr Borrero. “They have been very supportive of our work and we've done our best to provide the information they need to plan for an event that we hope never happens.”