Friday, August 27th, 2021 - The Easy Day We Wanted and How Come This Place is Here?

To insure that we would get into Terra Nostra today, Robyn volunteered to go down to the gate at 9 am to read her book and wait for the 10:30 opening. God bless her - when I moseyed down at 10 am, she was still the only person in line! At least we were the first in!

Pillars Beside Terra Nostra Gates

The Terra Nostra complex consists of a high end hotel, a world class botanical garden (in the romantic style) and a large hot pool. In the late 1700's people came to the area for the therapeutic benefits of the mineral waters. Around that time a Bostonian merchant built a summer house with a pool in front and an island in the middle. Then in the mid 1800's it was bought by the Count of Praia. With his wife they rebuilt the summer house and established the gardens which incorporated plants from all over the world. In 1935 a hotel opened on the property next door and a few years later the hotel purchased the house and gardens.

Terra Nostra Park House and Pool

Now I'm sure you were expecting to see a lovely clear blue lake from the previous description, not this muddy looking mess - but there it is - people come from he world over to swim in this! LOL!. The temperature was lovely and although it looks as if one is swimming in mud, it's actually just red, murky water due to the high iron content.

A Picturesque Nook at Terra Nostra Gardens

Before swimming, we decided to look around the 2 hectare park. Neither of us was energized, so we wandered aimlessly. In spite of our ennui, we couldn't help but notice some of its loveliness.

A Pretty Pond at Terra Nostra Gardens.

This little island was a popular spot for people to pose for photos.

Kangaroo Paw at Terra Nostra Gardens

I was surprised to discover that the brown plant in the middle of the lake was a kangaroo paw - a native of Western Australia.

Little Brown Duck at Terra Nostra Gardens

This little guy and his buddies were scrabbling around in the dirt near the small lake, too.

Avenue of Palm Trees Terra Nostra Gardens

This beautiful avenue of palm trees set us off back toward the pool for our dip.

Dippin' Dots at Terra Nostra Pool

So, in we jumped and had a lovely time lollygagging in the lusciously warm water. I do think it helps the joints lose their stiffness, so I have found all this 'hot bathing' quite beneficial. I could show you a photo of Robyn, too - just interchange her head for mine and you get the picture.

Huge Lily Pads at Terra Nostra Gardens

As I was leaving to head back up the hill, I noticed these huge lily pads in pools beside the path. The red flower on the left is also Australian banksia.

Volcanologic and Geothermal Observatory

Now, if I had not made my promise yesterday to return to vulcanology, this would almost be the end of this blog, but a promise made is a promise kept - so we'll see if I can provide a little bit of explanation for how these islands suddenly appear in the middle of this vast ocean.

 It all starts with good old plate tectonics - the scientific model which proposes that the rigid earth's crust is somewhat like a cracked eggshell - that the mantle acts like a fluid and these cracked portions of the crust float about on it. Where they interact with each other creates heat and disturbances depending on whether they are crashing into each other, diving under, sliding over, scraping sideways or spreading apart.

When I took Geology 101 in the early 70's, this was ground-breaking research that finally validated why the coastline of Africa and the Americas look as if they would fit together so well. It's now in 6th grade science classes!

The Red Lines Show the Boundaries of the Three Tectonic Plates Under The Azores

If you trace the north-south line on this diagram, you will find it is the same Mid-Atlantic Ridge that goes through Iceland and creates the vulcanism there. This ridge separates the North American Plate to the west from the two plates on the east. This East-West movement away from each other  creates new crust through the upwelling of molten mantle rock into the rift. 

Two of the Azorean islands - Flores and Corvo are on the western side of this ridge and are moving away from the Azores and closer to America by almost an inch per year! The guide at the observatory joked that SATA Air will have to change it's flight path before long!

The other red line that runs east west on the European side in the diagram above, divides the Eurasian Plate from the African (Nubian) Plate. The 9 islands of the Azores are where the two lines meet - an intersection of three tectonic plates, called a Triple Junction. https://en.wikipedia.org/wiki/Triple_junction

The most recent eruption occurred near Terceria from 1998 to 2001. It seems that it was mostly underwater and did not lead to permanent new land. 

Understanding what's happening between the Eurasian and African plates is not so simple - at the volcanology center they posited four different theories about what might be happening, including the existence of a possible Azorean 'micro-plate'. The only island that is clearly on the African plate is thought to be Santa Maria - the oldest island at 8 million years - very young in geologic time.

Rope Lava Display at Volcanologic and Geothermal Observatory

Suffice it to say, with all this stuff moving around at the intersection, a thicker crust below, along with some possible 'hot spots' (areas under the crust that are hotter than normal) - there is upwelling magma, friction and when they become large enough, can penetrate the 6,000 ft of water to create islands.

 Earthquakes are common - in fact the guide at the center here said there are earthquakes every day - mostly too small to be felt. She said the scientists worry when the earthquakes become less frequent, as it may signal a built up of tension that might increase the likelihood of eruption.

*Translation Below - I just liked all the arrows showing possible movement

This diagrams shows one of the four theories and is my favorite. At least it shows you where the islands are. 

I hope you're still with me. It fascinates me to see events in our lifetime that reveal how our earth is shaped - especially when it seems so very solid usually. 

The very first volcanic eruption that was observed from start to finish was here in the Azores near the island of Faial - the one on the African Plate that is nearest to the mid-Atlantic Ridge. It began in September 1957 and was first observed as very vigorous bubbles in the ocean by whale hunters. It became very active and for a while created a tenth Azorean Island near the Faial lighthouse. At first it was a fairly effusive, gentle volcano, like the Hawaiian ones, but then is became violent, throwing up ash that buried houses and eventually created solid land which joined it with Faial. The lighthouse still stands, but is no longer near the ocean, so it's a volcanologic museum. The eruption ended October 1958. The inhabitants were evacuated and many emigrated to the United States at that time. This link to a video below, is in English, and although it is longer than others on youtube, it gives a good historic background, especially with regard to the relationship of the Azores to the USA.

https://www.youtube.com/watch?v=QB26Uk1xQwM

Map Showing The Timeline of the Creation of Sao Miguel.

Now, don't be scared - this one is easy. 

I just loved the three dimensionality of this little map and the historic and quite recent tale that it tells, especially having just visited many of these places, so they are no longer just names.

It basically shows how Sao Miguel was formed - the yellow section to the east was Nordeste - it was first at 4 million years old. It was effusive - like Hawaii - no big drama. The next was the pink, which was 3 million years ago. Then there was the blue, Furnas - around 750,000 years old - and it was explosive.

 But here, the steady east-to-west progression ends and we jump to the orange - which is Sete Cidades and it was a big bang. So at that point, Sao Miguel was two islands. Next, we go back to the addition of the green section, Fogo - which was 250 thousand years ago, also explosive - and finally the two halves joined together with the eruption of numerous stromboli type vents in the brownish/grey section which began about 50,000 years ago. In this area there are approximately 235 small volcanic cones, many of them younger than 10,000 years.

You might note just a little brown section up by Mosteiros, which explains why is doesn't have the cliff-like drop to the ocean, but is a gentler slope instead. It also shows faults on either side - indicating it dropped to the lower level - called a graben. 

Aerial image of Sete Cidades from Brochure at Volcanologic and Geothermal Observatory

The last tid-bit I leave you with is a correction about the reason Sete Cidades (which I learned is pronounced 'Set Sidash') is called 'Seven Cities'. It was because they identified seven different volcanic vents within the one caldera. See if you can find all seven from this photo. They just connected this number to the other mythical stories I had mentioned earlier.

Cosido, or Furnas Stew

So now you can understand how it came about that I was able to enjoy a lovely pot of meats and veggies that was cooked with nature's largesse. The meat was very tender, it had a smoky flavor and was very enjoyable in a hearty way. It has been a long time in the making - not just the 6 or 7 hours it sat in the hole - but the eons of geologic activity that allow people to walk on and create things with its energy.

For me it was a very satisfying meal! 

I hope you also found this story digestible - but I suspect not quite so tasty! LOL!

Translation from plate tectonics diagram above - (per Google translate!)

* A second theory qualifies this rift as a  'leaky transform' fault driven by a joint movement of retraction and sliding. These complex movements would give oblique tensions to the region. This model fits well with the geology of the islands, provided that the rift passes easily by Sao Miguel, Terceira and Graciosa, and that this limit bifurcates more or less at the level of Faial-Pico-Sao Jorge.