Life in a Dol house
2016 - Week 44

Becoming involved in citizen science

Thanks to those of you who enquired if the earthquake in Italy on Sunday had affected me. 

I was up early, because of the change of the clocks and can say I felt nothing at all.

A few years ago now, I was in Santa Clara County, California, less then 30 miles from the 1989 Loma Prieata earthquake epicentre in the San Francisco Bay area, the one where the freeway collapsed, so I know what an earthquake feels like. The events this past week did lead me to do some research though, for a couple of reasons.

Firstly, all my buildings being 100+ years old, are of similar construction to the ones in Italy which have disintegrated - stones of varying sizes, held together with lime mortar, very thick walls, the centres filled with stone rubble and sand, and the inner and outer faces not tied together. But secondly and more worryingly, I know that there have been recent tremors centred on a fault line to the north east, near to the neighbouring island of Brač.

Having been involved in earthquake preparedness in Abu Dhabi, with the police and the then fledgling NCEMA, I have some familiarity with the terms which the plate tectonics experts bandy about. Although I have seen (and felt) very much at first hand this destructive force of nature and some of the quite bizarre results, for example this land drop after a quake on the infamous San Andreas fault, I honestly could not tell the difference between a Thrust fault, a Dip-Slip fault and tectonic uplift!

The whole of the Adriatic basin, part of Southern Italy and to the north, southern Austria sits on our own, small tectonic plate, called the Apulian Plate.

It was on the north western side of this microplate where the earthquake on Sunday took place and where all the recent seismic activity in Italy has occurred.

 But what did surprise me is seeing the number of small fault lines, which on my side of the Adriatic all run in a roughly south-west to north-east direction and pepper the plate, including one skirting the south coast of the island of Hvar.

Perhaps the most well known earthquake in this area, with a strength of 6.1 on the Richter scale, took place on the fault just off the coast of Makarska on the 11th January, 1962. It devastated the villages around the town resulting in population changes which are still being felt today. Being so close to Hvar, it was felt and is remembered here still.

Because the Adriatic Sea is relatively shallow, there was no large Tsunami last week. In the European TRANSFER database (Tsunami Risk ANd Strategies For the European Region) there are 15 Tsunami events recorded for the last 600 years for the Adriatic.

There are a lot of interesting maps available, but two in particular caught my eye, this one identifying in coloured zones, fault lines in Croatia and the locations and magnitude of recent earthquakes.

And a second one which shows the geology of the island of Hvar.
The map clearly identifies thrust faults (9 in the key) which run east - west along the length of the island, and reverse slip faults (10 in the key) that cut across at diagonal angles. 

The cross section between points A and B, runs just to the east of Dol and clearly shows the complex folding that has taken place over the eons.

But what does all this add up to? There is no requirement in current local building codes to make buildings earthquake 'safe'. The country had an opportunity to apply more stringent criteria, but shied away from it because part of the city of Split would be in one one zone and part in another causing enforcement problems, so they went for the lowest for everyone. A typical European fudge! It will be a discussion I will be having with my architect though...

Regular readers will be aware of my battle with the weeds, but also my attempts to be sympathetic to the surroundings of my Dol house, trying to understand the ecology and working creatively to increase the ecological value of where I live.

 One of the very first things I did was to comprehensively measure and map the gardens and orchards, identifying the trees and plants I have, and also through photography and my weekly musings, to record the wildlife I come across day by day, week on week throughout the year.

My weather station uploads data every five minutes of the day to various organisations, to help with international understanding of what is happening in my tiny corner of the world, and to add to the bigger picture of climate change. This is what is called "Citizen science". But here in Croatia the concept, like many things, is neither well developed nor really understood.

Many citizen science projects, like the BBC's Autumn, Winter and Spring watch are not available here, and there is no European alternative. 

This week with my neighbour, we have photographed a number of the winter migrant birds, arriving to over-winter here, whilst almost all our summer visitors have left. But there seems to be no way to record these sightings. This is a Black redstart, Phoenicurus ochruros).

And a wagtail

So it was with great interest that I listened to one of my regular Podcasts called "A way to Garden", by Margaret Roach, from American National Public Radio. This week it was all about participating in the Habitat Network.

I have joined and have mapped my orchards. I need to put a lot more detail in, especially in the Top Orchard, which is still a fairly blank although rather weed covered canvas. I look forward to learning from this worldwide network.

So let me pose a question, what have YOU done to be involved in citizen science and to help improve the knowledge and understanding of our world for the benefit of all mankind? 

In the UK, USA and Australia, there are huge numbers of projects from reporting sightings of bats, butterflies and hedgehogs, to participating in helping to map the change to the climate through Spring and Autumn watch.

There may be something you can do where you are, which by adding your observations will add to the sum of human knowledge. If you can, I would encourage you to do your bit, for our children's children.

On the subject of weeds, sometimes I feel I am not alone with a weed problem
This is a small field I pass every time I go to Stari grad.

It looks rather pretty in the warm, autumnal sun, except all those yellow flowers are Creeping Buttercup, Ranunculus repens, listed as an invasive species. The more you dig them in, the more the stolons spread. A really strong systemic herbicide is the only way to get rid of the problem.

Meanwhile in the sun this week, I have spotted a number of my residents. 

This brown adult male Praying Mantis, Mantis religiosa, was hunting for insects around some fallen Pomegranate fruit. They do not survive the winter, so sadly, once we have some cooler nights, they will disappear.

I find the Mantis quite an endearing insect. Whilst we cannot ascribe intelligence, in the way we understand it, there is something going on inside the "grey matter" because Mantis turn their heads, swivel their eyes and focus their gaze on you. 

There are several hundred different species of Mantis, but this one I was able to positively identify because of a distinguishing dark spot in the armpit of the two front grasping arms.

I also rescued a very large caterpillar from one of my neighbours felines
It was thrashing back and forth while the cat smelled it and tapped it with a paw.

It is a Convolvulus Hawk Moth caterpillar, Agrius convolvuli, which with the number of twining convolvulus weeds I have, I am not surprised to see.

The adult has a wingspan of more than 100 mm or four inches.
After being rescued, I brought it inside in the hope that it would calm down enough to uncurl and be measured. It didn't, resolutely remaining in a 'U' shape and so I let it go, putting it near to some of its favourite food in the Top orchard.
The dragonflies are still flying and this specimen was sunning itself on my Goji berry bush

Despite the highly distinctive orange and white flash on the leading edge of each wing, I have been unable to identify it. But what I have been told is that dragonflies wings are only shiney immediately after they emerge from their pupa case. But as there is no water anywhere near, it begs the question that if this specimen has just emerged, where were the eggs laid?

I've been helping my neighbours with the removal of the high hedge which formed part of the northern boundary of the orchard.

A small chainsaw cut all the greenery off the tree trunks. This has been piled up into two large mounds n the orchard, so I can shred it and then use it as a mulch.

With rain forecast for the next week, I have covered the piles with some plastic to keep the worst off, so that I don't have to wait for it to dry before I can turn it into a useful garden product.

The individual trees, which had been planted just 30 cm apart, were then removed using my 1.5 tonne hand winch and the resulting logs have been piled up to dry, before I can use them as fuel in the wood stove.

There is a lot of wood and green products to be disposed of, but the thing which struck me was how much more light now floods into the orchard, now the 3 metre high and metre wide hedge has gone.

It will be replaced with a two metre wall built from local stone, but as on my side the wall will be south facing, I will gain huge benefit from the reflected solar energy and from the heat it will release to benefit some tender shrubs and trees, yet to be planted in the orchard.

Isn't it strange how your memory plays tricks on you? 

I thought that the autumn in 2015 was much warmer than this one. But a quick analysis of my weather data suggests they are almost the same.

October/Year        Max temp         Min temp          Average        Precipitation 

2015                         34.3ºC             12.3ºC            21.9ºC          68.1mm  

2016                         30.2ºC              10.3ºC            19.8ºC          55.9mm

So 2015 was very marginally warmer over the month, but not substantially so.

 And with that, it is the end of another week.