It’s been almost two weeks since our trip to Savo, and I’m sure some of you were wondering when our next post would be. Well, we’ve had a busy, but productive two weeks, and having shipped off our samples back to Leicester yesterday, it felt time to post what we’ve been doing and some of the exciting developments we’ve had.
After recovering a bit from our trip to Savo (good as it was, crossing the Iron Bottom Sound in rough seas leaves you worse for wear) we headed back into the office to look over what we had collected – Logs, Samples, Photos and set to correlating these with our next few days in the office. Not exactly thrilling work but just as well as the weather here has become pretty abysmal! Several of the last few days have seen us in the office with torrential rain lashing down outside. Good thing we had some logs to correlate… This of course is something that will go on once we return to
When the weather did hold up we also visited the Solomon’s National Disaster Management Office (NDMO). We met with the organisations director, Loti Yates, who was more than happy to supply us with the current information about Savo. This included schemes to help mitigate the effects of any future eruption on the island such as the setting up of regional committees to marshal evacuation plans as well as past government/international initiatives such as Exercise: Long Reach. However, no current integrated plan of the effects of an eruption and measures to mitigate them has been drawn up by the NDMO, and Loti hopes that the data we produce (along with the great work of others at Leicester) could form part of a new integrated plan to be developed in the next few years.
Further to this, we may have opportunity to utilise topographic data provided by Claudia and the Government Lands Division, along with data we have collected to help simulate flow down the Rembokola Valley. This has been suggested by Leicester’s own Dr Rebecca Williams and although in a very early stage, and requiring a full DEM (Digital Elevation Model) of Savo to help make possible, this does sound very exciting and promising. We have chased down two copies of such a DEM, one held in the records of the Lands Division, and one by a former member of Claudia’s research team. We hope to obtain the Lands copy by Monday. Though this is extra work for us, the hope of feeding in new scientific data to a full disaster management plan for Savo is a big impetus. Hopefully the data for this, particularly the DEM will materialise. This is something we had not expected to come out of this trip, but marks a welcome addition to the work we are doing out here. Thanks Becky!
Returning to our other work here, Greg and I have been looking at the infrastructure around Honiara’s main districts to ascertain resilience to other natural hazards and the potential impact an eruption on Savo could have to this area. Speaking to Loti, the major fear is of a tsunami being triggered by any eruption of the nearby island. Having frequented Honiara over the last five weeks it seems that the city may be woefully unprepared for such an eventuality, but we will be discussing with the NDMO the likelihood of such an event and what can be done over the coming days, and feeding our findings back to him. More on that next week.
This final week has flown by, and the data Lands Division and the NDMO have supplied us will hopefully augment our own data and go a long way to helping improve plans for Savo and the Honiara area. With today being our last Friday in the office, it’s good to be leaving with a sense that the work we’ve been doing out here may go on to be part of something bigger. Here’s hoping we get that.
“Our trip to Savo is now complete, and looking back on it I’m reminded that what you plan and what actually happens are often two very different things. Don’t let this sound like a bad thing. Greg and I have both come back feeling great about the work we’ve done and the experiences we’ve had on the island, but last Monday morning that almost wasn’t the case…
As you know, we have been staying just outside of the capital, Honiara, here on Guadalcanal, and the trip to Savo is an hour or more by motorised canoe. So at the crack of dawn on Monday we set off for the docks to get an early start on the island and get straight to work. Our boat arrived just after us, but was unfortunately having engine trouble, which quickly moved from “we’ll fix it in an hour” to a “not until tomorrow”. Obviously carrying all our equipment and supplies we were eager to get onto the island, so after mid morning it became for us Savo: by any means. Ramo, our attaché from the Survey worked hard to get us a new passage, and we had little choice but to go and wait at a nearby café, the Lime Lounge. Not feeling great at having lost a day and possibly more cash, we settled in… until we got extraordinarily lucky.
Another researcher, Claudia (who we had met on the flight out here), also working on a project on Savo was in the café and had a boat leaving that day. We had a chat about our respective projects and she offered us passage aboard the boat going out that day. Whilst we arranged this, she took the liberty of showing us several datasets which her team had already taken from Savo, including a digital model of Savo’s topography. Whilst loosing a few hours and a boat ride, we’d struck gold, and we took it as a good sign for the rest of the trip.
We had a calm crossing across the Iron Bottom Sound and reached Lemboni by mid afternoon, where the local chief greeted us, showed us around and explained some of the areas history, including its time as a coconut plantation prior to the Second World War.
The next few days were spent doing what we came for: Working up and down the coast and locating good sections to log (and having to keep one good eye on the tide), mapping infrastructure and talking to local residents about the volcano.
"Some of the wonderful cliff section we got to study below the Lemboni plantation"
This last part was particularly interesting, as those we spoke to were well aware, through kastom stories that living in the shadow of an active volcano can be a dangerous business, but many were unaware of the principal hazards they may face. Evacuation plans and, crucially, areas to evacuate to have been put into place for the whole island, but there is a general feeling among the villagers that plans will not work 100%, and distribution of these plans and evacuation areas is not as widespread as it could be.
We had the opportunity to speak with the principal of the local school in Paimbeta (just south of Lemboni), who aired some familiar concerns, and stated that the threat of an eruption is always overshadowing the community, but that awareness is improving. In 2010, a team from the Geological Survey, including Professor Mike Petterson (University of Leicester/GfGD Advisory Group), made a presentation to students about the volcano and the hazards it poses. There is a hope that the survey can expand on this and revisit the school, as well as others across the island to spread awareness of an eruptions effects and how people might prepare and protect themselves. Hazards, including volcanic hazards and more frequent cyclones, are now taught as part of the school curriculum at Piambeta. For the younger generation of islanders, awareness and knowledge are steadily improving.
"A list of evacuation sites along with maps detailing hazardous areas, on a notice board in Lemboni. We were told this is the only one of its type in the area."
A testament to how necessary this is was seen by us along the Rembokola River, where fresh flood deposits from 2010 were clearly visible. Though these did no damage to the surrounding villages, I was reminded of similar events and the lahars reported in 1953 on the island, and the hazards such future events may pose. The islanders however simply consider these a fact of life.
Speaking of which, our trip coincided with a local change in weather, what islanders call “Komburu”, signifying a change in wind direction bringing worse weather. We experienced the full force of this on our journey back to Honiara, when our small canoe was buffeted by 5 foot waves and had several sharp rain showers during our stay. Even here you can’t do fieldwork without it raining.
Infrastructure on the island itself is pretty basic. Being a small island the only direct means of transport is by boat or by foot, along tracks throughout the village. Water is obtained through rainwater collection and many other supplies are brought onto the island by canoe from Guadalcanal. Chief Melchoir explained how vital this is to the island, going on to say that during a bad hurricane season (such as the one in 1986) the island can be cut off for a time causing a
great deal of hardship.
Having logged several coastal sections, we ventured in land to locate some proximal deposits further up the Rembokola valley. With waterfalls of boiling water flowing inches away from us at times and virgin rainforest all around, this is a journey I won’t quickly forget. A good proximal location did however remain elusive to us, but a visit to the crater more than made up for this.
"A waterfall we encountered on our trip up to the crater, with the water near boiling point from geothermal activity"
Savo proved to be a fantastic place to work, and we were both sad to leave, but now we hope we can expand from the work undertaken there to produce something worthwhile. Our thanks go out to the local team guides on Savo, our host Micheal Dokoa, Chief Melchoir and of course Alun Ramo.
"Some of the team who helped us on Savo. From left to right: Savino Turavalo, Simon Dokoa, Greg Smith, Alun Ramo and Stanley Sado."
Today we will be taking the Survey’s motorised canoeacross to Savo first thing Monday morning, and will be staying until the weekend. The coastal area around Lemboni which we are studying is one of the more populated flanks of the island and hosts major infrastructure such as the local high school, just down the coast from where we are staying.
Once on the island we have our work cut out.We plan to begin by mapping out the infrastructure of Lemboni village itself and the surrounding area at the exit of the Rembokola Valley, and hope this will give us ample opportunity to practice our Pijin (the local language) and explain the purpose of our trip to people.
After this we will spend two or more days along the few km of coast representing the landward edge of the Rembokola fan, searching out suitable sites to draw up graphic logs and beginning our work characterising the deposits in this area. Logging [measuring and describing the different geological units in an area] is one of my favourite field exercises (though many of my friends back in Leicester give me a puzzled look when I tell them that) and I can’t think of a better place than coastal cliffs on a tropical beach front to do such a thing.
This will take up the majority of our time, as we want to log, sketch and photograph these areas in detail, as well as collect samples for later use in projects. However, having mapped out local infrastructure and topographic areas, we also want to question villager’s perceptions of the volcanic hazards they face and any precautions or evacuation plans they have in place, what role the government has to play.
Our research so far indicates that the people of Savo have their own plans and concerns about the volcano, along with many residents here on Guadalcanal, the main island. Relating our work to people around Kakambona, most people ask as two things: “Will it erupt?” and “How will it affect us?” – Both pertinent questions for those who live in sight of avolcano. We look forward to the questions, and answers, the people of Savo have for us, and hope we can inform and reassure the islanders a little more on completion of our work.
'Last week I spent 4 days mapping a stretch of the Putih River, or 'White River' as it is translated into English. This involved marking in changes in channel dimensions and defences, to produce a mini hazard map. With review and comparison to previous maps I can create an updated report of the area. The exercise has been more than useful in helping towards my 4th year project, being able to see first hand how the river interacts with local communities and the impact the lahars have. I was accompanied on my visit by a student from Gadjah Mada Uinversity, who was able to help me communicate with the locals. They are able to provide information on lahar duration and magnitude for the past two to three years at specific locations, as many villagers do not move out of the area despite the hazards. We also spoke to an engineer who was assessing the quality of the defences that are currently being constructed and he gave an in depth explanation of a new type of dam they have installed that will hopefully minimise the risk of damage further downstream (see the first photo below, the engineer entitled this a floating dam). A destroyed dam on the Putih river is shown in the second image below).
What has struck me more than anything is how resilient the local population are. Where bridges have been destroyed they merely construct new ones, (quite often out of bamboo which looks marginally dangerous when I see motorbikes using them - see the photo below), and where houses have been knocked down they simply rebuild. The river is also a major source of income to them and their excavation of material generally helps conditions during the rainy season, removing material that would otherwise be reworked. Issues do arise if they dig too close to the dams, which can risk the structure being undermined.
Overall the government seems to have the river well maintained; it just requires constant maintenance. With Merapi erupting so frequently there is a constant supply of material to be washed down every year; it's not like the problem will disappear after a few years. This means that hazard maps need to be constantly assessed - if the volcano erupts in a different direction then a different drainage basin will suffer from an influx of material. On a wider scale it is important to note that fluctuations in the rainy season have been increasing, possibly due to climate change, and so it is hard to predict when the lahars will occur. This could be an interesting topic to investigate.
From Wednesday this week I have been tasked with mapping the Krasak River and hopefully I will be able to compare the two rivers after this exercise.'
In a few days we will be departing to begin a six day spell on Savo Island, an historically active volcano in the Solomon Islands arc. It lies just 35km away from Honiara, the capital of the Solomon’s, so assessing the hazards it may pose is crucial to safeguarding lives and infrastructure in the area.
Once on Savo, we will be staying in Lemboni village, situated on the NE coast of the island. With this as our base, we will study the block-and-ash flow deposits (those left by pyroclastic flows at previous eruptions) in the vicinity to get a better idea of Savo’s eruption products, their behaviour and the hazards they pose to the islands population.
Our work can essentially be divided into two separate project areas.
The first one involves the study of the coastal fan deposits created by block-and-ash flows as they have exited the various valleys on the island (we will be focusing on the Rembokola valley above Lemboni village, whose deposits have been allocated to a period of activity during the mid-19th Century). Through logging, sampling and studying these deposits we hope to better understand the nature and behaviour of BAF’s on Savo and how they may behave in future eruptions.
The second project involves assessing the risks such hazards may pose to coastal villages such as Lemboni. This will involve analysis of how hazards move down the Rembokola valley and how a major life threatening hazard would interact with the villages and local environment. This could lead to the construction of a hazard assessment map to indicate “safe zones” in the area where villagers may go to seek shelter from such a destructive event. We will also aim to assess the preparedness of local residents by surveying the population of Lemboni, as well as its infrastructure, to test the strength of its evacuation plans and local education about the dangers that Savo poses.
To aid in this, Greg and I have been practicing our Pijin (the local dialect), which we hope will allow us to interact better with the villagers and more easily understand their perceptions and worries about the volcano.
Both of us hope this work will be worthwhile and give as much benefit to the communities we visit as it does to us.
We’re waiting on the Survey’s boat to return from the Western Provinces to ferry us over to Savo (this should be sometime between Thursday and Monday, as the survey have to check it over from its last trip before we leave. We will have a personal attaché from the Geological Survey Division for the trip and have been put up in Lemboni by Chief Melchoir, the head of the village.
David writes... "Here are some photo's from our past few day's on the islands of Guadalcanal in the Solomon Islands. The first photo is of a Greg at a waterfall on the Mbisi river, about two hours walk south of where we are staying in Kakambona. Some of the village children took us up river at the weekend, and the sights are pretty amazing (and the river cuts through the geology quite nicely). We will be returning that way this weekend to see more of Guadalcanal's interior and take our field notebooks this time.
The other two photos are of part of the village of Kakambona as seen from Leonard's house and Leonard's house itself. Leonard works closely with many visiting students on the Solomon Islands, helping to arrange accommodation and travel.
Just to give you a quick round up of events so far, we have been gathering our resources (food, water, maps, log sheets and other equipment - I fear we may have to take a kitchen sink!) for the trip out to Savo Island. We will be staying in Lemboni on the north east of the island in order to study the block and ash deposits of the Rembokola valley, and hazards posed to the villages in this region by future volcanic activity. The survey's boat will be returning from the Western Provinces next week, and once it does we will be off!"
David Writes... "Today was our first real day 'in the office' following the weekend, so we've just spent the day mapping out our project work. Everything looks good!"
Greg and David have reached Honiara, Capital City of the Solomon Islands, after several days of travelling! Over the weekend they'll be planning their work in more detail - determining how to go about their fieldwork and hazard mapping. The M6.5 earthquake earlier this week is a reminder of the importance of this type of work in the Solomon Islands.
Greg Smith and David Cavell today travelled out to the Solomon Islands to undertake fieldwork there, working with the Geological Survey.