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Urzelina (volcano)
Encyclopedia
The Urzelina Volcano was a volcanic eruption that occurred in 1808, from a fissural cone along the island of São Jorge in the Azores, responsible for the destruction and deaths in the community of Urzelina
, Velas
, producing a basalt
field of volcanic rock extending to the Ponta da Urzelina. Curiously, the eruption was the last sub-aerial event observed in the Azores; most recent eruptions have occurred along submarine vents, with the Capelinhos
eruption (1957-58) starting as a submarine eruption (that eventually grew into a sub-aerial event) and the 1998-2001Serreta
eruption being exclusively submarine (never breaking the surface).
The events of the eruptions were reconstructed from various descriptions after the event, the most significant coming from Father João Ignácio da Silveira, parish priest of Santo Amaro
. From these accounts, he wrote of a great cloud of fire that grew above the parish of Urzelina which was followed by abundant ash showers.
A similar account was described by João Soares de Albergaria de Sousa
, in the quasi-political document Corografia Açórica
:
The volcanic activity continued until May 4, from several points above Urzelina, migrating to as far as 1.5 kilometres towards the direction of Entre Ribeiras. The parish of Santo Amaro was also affected on May 11, when two craters in the area of Areias, began expelling lava which forced the evacuation of the population.
Fifteen days after the initial eruption, explosive activity occurred again above Urzelina. This new episode was accompanied by the production of lava that destroyed a great part of the parish, fostering gas clouds and nuée ardente
that caused the death of thirty people.
In the Revue Scientifique de la France a de l’Etranger, Ferdinand André Fouqué
writing on the eruptions of 1580 and 1808 verified, in the two craters that he investigated the implications of the pyroclastic flows:
A similar description was complied by João Teixeira Soares; writing in the O Jorgense (numbers 21, 22 of August 15 and September 1, 1872)He was a little more specific noting that in the timeline of the events, that around June 5, ten days after the first emissions covered the island, fumes flowed to the east and west, causing a large surge in temperatures and devastating the vegetation.
These suffocating gases, which were probably carboxylic acid
, were harmful to the population; the thick water-vapor, which condensed in a reddish color, rapidly spread unnoticed through the local vegetation (a mix chloric
and sulfuric acid
s) which were expelled as aqueous vapors.
Physically, the events was centered on seven craters, in the area known as Lagoinhas, and its effects were most prominent around the area near the Church of São Mateus. The temple itself was survived by the bell-tower, which became an ex-libris for the island of São Jorge. Even following the eruption, gas emissions continued to be observed from the craters and lava flows.
Captain-General D. Miguel António de Melo
, realizing the need of the islanders ordered, in a May 18 decree, the free distribution of five moios of corn: recommending that they should plead for "divine mercy" while offering his assistance on the island, if his presence would assist their cause. In a letter dated July 23, the municipal chamber accepted the General's offer of cereal and foodstuffs, but the writer, José Félix Rodrigues Mendes, added:
The intent of the request was to free some serf
s to assist in the reconstruction, but the Civil Governor and Captain-General, responding in an angry letter, dated October 21, were insulted by the letter's signatories, demanding that those who had signed the document should have their functions suspended (resulting in José Félix Rodrigues Mendes's suspension from the municipal chamber). Out of personal spite, the Captain-General continued that he: "...had, for similar absurdities, run to ground António Sebastião Espínola for these type of ordinary strategies...you deserve that I order your apprehension and have you arrested on my order...!!!"
, Terceira
and São Miguel
) from June 5 to June 10, or felt continuous earthquakes during the event (as was the case on Faial
and Pico
).
The several earthquakes that occurred during the events motivated officials in Horta
to send personal assistance to the island; in this case a contingent of residents traveled to Velas
in order to offer support and their hospitality to many of the local people affected by the crisis.
The church's parish priest, José António de Barcellos, wrote later (per the writings of João Teixeira Soares), that the event was both an act of God and divine providence, since for years he had requested assistance for the construction of a new parish, and received evasive responses. It was during the governance of Captain-General Francisco de Borja Garção Stockler
, after the 1808 eruption, that he was able to raise the costs and through sacrifices, construct the new parish.
The effects of the eruption even persisted to 1810; in that year, three men were asphyxiated when they attempted to clean a salt-water pool along the Urzelina coast (which they had discovered to have been polluted with ash). During excavations made in June 1877, in addition to many ruins, the house once owned by Jorge Soares de Avelar was discovered.
Urzelina
Urzelina is a parish in the district of Velas in the Azores. The population in 2001 is 866, its density is 63.4/km² and the area is 13.67 km². It is also known as São Mateus....
, Velas
Velas
Velas is a municipality in the São Jorge Island, in the Portuguese autonomous region of Azores. The municipality encompasses the western portion of the island, with its municipal seat in the town of Velas on the south coast and divided into six parishes....
, producing a basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
field of volcanic rock extending to the Ponta da Urzelina. Curiously, the eruption was the last sub-aerial event observed in the Azores; most recent eruptions have occurred along submarine vents, with the Capelinhos
Capelinhos
The Capelinhos is a monogenetic volcano located on the western coast of the island of Faial in the Azores. It is part of the larger Volcanic Complex of Capelo, that includes 20 escoria cones and lava fields that are aligned west-northwest to east-southeast from the Cabeço Gordo caldera...
eruption (1957-58) starting as a submarine eruption (that eventually grew into a sub-aerial event) and the 1998-2001Serreta
Serreta
Serreta is a parish in the municipality of Angra do Heroísmo on the island of Terceira in the Azores. The population in 2001 was 374, its population density was 26/km², and the land area is 14.36 km². The parish lies at an elevation of 471 metres...
eruption being exclusively submarine (never breaking the surface).
Eruption
In the late morning of May 1, 1808, after a few days of intense seismic activity (that produced approximately eight tremors per hour), a fissural eruption occurred in the foothills of Manadas. Its eruption, which also affected other districts, was followed by gaseous emanations and lava flows that caused several deaths and destruction in the parish of Urzelina.The events of the eruptions were reconstructed from various descriptions after the event, the most significant coming from Father João Ignácio da Silveira, parish priest of Santo Amaro
Santo Amaro
Santo Amaro, is Portuguese for "Saint Amaro" or Amarus the Pilgrim, but may also refer to:-Portugal:*Santo Amaro , a civil parish in the district of Sousel...
. From these accounts, he wrote of a great cloud of fire that grew above the parish of Urzelina which was followed by abundant ash showers.
- "On the early morning of Good Pastor Sunday, the first day of the month of May of the present year 1808, the earth shook so frequently, that we counted about eight tremors per hour, and of these there was one near sunrise so big, that it woke the population from their beds. On the same day, with part of the people in the Church supplicating themselves to Our Lord God, there was another earthquake that caused the assembled people to flee the Church, from 11 to 12 of the same day there were other earthquakes, and closely a sound so loud...and quickly we saw arise a great cloud of smoke over the tallest mountain of the parish of Urzelina, on the peak of António José de Sequeira, and in front of the Church of São Matheus, whose plan is central to the parish and was the most pleasing on the island, and for that reason it is visited by many good and bad people of all the islands, and in a short time it covered the highest sky made an arc over the parish of Manadas and of Urzelina..."
- From the mouth of that volcano existed roars so great and trembling without interval that it invited the inhabitants of this island to Judgment. The people ran to suplicate themselves to God, quickly the people of the parish of Urzelina were afraid and abandoned their vicar the Reverend José António de Barcellos in the sacristy of his church, and in the same day it rained so much sand that the homes in the headlands were covered with sand and the fields there remained with [a thickness] of 7 palms [height], and the vineyards of the Castelletes until the chapel of Santa Rita, in the parish of Manadas, remained fixed and the homes almost collapsed with the weight, immediately escaping tongues of fire from the center that reached the heavens, throwing ignite rocks to 8 palms, to a distance of four leagues, others of 16 palms or less, rose to the same height and fell in dense showers."
- Arriving the tragic evening, it dis-animated the inhabitants of this island to see the fire and ignite rocks, that escaped as meteors and almost looked like they fell over the people, and the windows of the church almost appeared to break with the echos of the sound that threatened our life."
- Until Tuesday, third day of the same month, there exploeded fire from seven places, placing the mouht of the volcano close to Ribeira do Arieiro, by afternoon the fires had abated: in the morning of Wednesday, fourth day of the same month, there exploeded a fire between Ribeiras, above Fajã's spring, and with the same luck, it created a a cloud of sulforous powder and dirt that appeared to burn that location.
- The vicar of Urzelina quickly made a procession to the area of the fajã with [the image] of Senhor Santo Christo and Nossa Senhora das Dôres, eventually meeting Father José de Sousa Machado, who brought a procession with Nossa Senhora da Encarnação and vairous people, who were almost suffocated by the sulfurous powder that was falling. Joining that animated procession, they arrived at the chapel of Nossa Senhora do Desterro, and still, with a lot of effort, because at the intersection to the top, there fell much sulphur and the air was sticky that many trees fell with their weight, while its character affected the travellers.
- After another seven days, a fire exploeded in the vicinty of the parish of Santo Amaro, where it opened two mouths of fire, such as two great ravines of fluid material, and with such force that on the second day, we encountered more than a moio of fields of lava in the direction of the homes, forcing the people to flight, the vicar, Rev. Amaro Pereira de Lemos, lost his senses and sister D. Anna Maria de Lemos, went crazy.
- The Vicar of Velas and Confessor, the Rev. António Machado Teixeira, upon the fire reaching the village was worried that they should leave, and ordered that the Sacremento should be sent to Beira, resulting in an abandonment [of the area] that could not be explained. The nuns went to the Church in Rosais; the Confessor and other clegry to Faial, the Judge to Pico and and most of the people, almost the entire village, went to Beira and Rosais. This movement was beyond necessity, because on the day they did, those who saw the fire noted that they barely ran, and mostly within the ravines
- The hinterland where the mentioned fire passed remained beaten and the grotoes formidable, the road broken in a manner that there did not pass cars nor people.
A similar account was described by João Soares de Albergaria de Sousa
João Soares de Albergaria de Sousa
João Soares de Albergaria de Sousa , frequently referred to as João Soares de Albergaria, was a liberal politician, rural property-owner, and author of the histo-cultural manifesto Corografia Açórica, which was published in 1822, the first Azorean thesis on regional sovereignty.-Biography:He...
, in the quasi-political document Corografia Açórica
Corografia Açórica
Corografia Açórica was Azorean political document produced in 1822. Its full title was Corographia Açorica, ou Descripção Phísica, Política e Histórica dos Açores, por um cidadão açorense, M...
:
- "The volcano of 1808, that we witnessed erupt from Lagoinhas, along the massif that lies to the north of the village of Urzelina, also expelled from the locality of d’Entre Ribeiras, a league to the north-west of that area and then later in the area of Areias; the first tongue expelled for many days great quantities of material: for seven days the sun was obscured from the density in the atmosphere, impregnated with volcanic vapors; there were ash showers; the island suffered many and violent concussions; the soil in the neighborhood of the volcano opened deep cracks; these faults opened in areas 88-132 centimeters. This volcano ran to the sea, without interruption, leaving the ground covered in lava to a height of 990 centimeters, approximately."
The volcanic activity continued until May 4, from several points above Urzelina, migrating to as far as 1.5 kilometres towards the direction of Entre Ribeiras. The parish of Santo Amaro was also affected on May 11, when two craters in the area of Areias, began expelling lava which forced the evacuation of the population.
Pyroclastic flows
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
that caused the death of thirty people.
- "The volcanic activity ceased, but gradually; the craters smoked still for many days, and for many years it was perceptible near the faults...a major elevation in the temperature, marked by Herbaceous plants that covered the soil. The lavas conserved, also, for years, sulfurous gases...Of the phenomenons that we related, that which appeared to give the most attention of the geology, was the nuée ardentesPyroclastic flowA pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
...They were laden with a humid powder or dough, making them heavy and obligated them to fall to earth, down the flanks, to the sea. It brought with it a terrible force of transference. The introduction of the lightest part into the respiratory organs caused death. An identical phenomenon appeared, as we saw, in 1580...The lava of 1808 is the most attractive that one would know in geological history. Many parts of it are already converted in branching mats. A graphic representation of the craters and lava from one or other volcano have shown notably their history and relations."
In the Revue Scientifique de la France a de l’Etranger, Ferdinand André Fouqué
Ferdinand André Fouqué
Ferdinand André Fouqué was a French geologist and petrologist.He was born at Mortain, in the Manche département....
writing on the eruptions of 1580 and 1808 verified, in the two craters that he investigated the implications of the pyroclastic flows:
- "These nuée ardentePyroclastic flowA pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
were laden with humid powder, that descended along the flanks, lightly touching the surface of the terrains. This toxic contact wilts and kills plants immediately...The asphyxiating power of these clouds, their progress close to the surface of the soil and the constant movement along the slopes indicate a principal element...the existence of a killer and dense gas, probably indicates carbonic acidCarbonic acidCarbonic acid is the inorganic compound with the formula H2CO3 . It is also a name sometimes given to solutions of carbon dioxide in water, because such solutions contain small amounts of H2CO3. Carbonic acid forms two kinds of salts, the carbonates and the bicarbonates...
. Its opacity is attributable to water vapor, mildly condensed and its reddish color, a volcanic dust, so subtle that it is dragged in a suspended mixture of gases and vapor. In the end, the actions upon the plants, prove without a doubt that chloric acid and sulfurous acid expelled in conjunction with aqueous vapors were dragged with it. The testimonies from the 1808 eruption do not refer to flames; the descriptions that were left, makes one conclude that the temperature of the nuée ardentesPyroclastic flowA pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...
were low temperature."
A similar description was complied by João Teixeira Soares; writing in the O Jorgense (numbers 21, 22 of August 15 and September 1, 1872)He was a little more specific noting that in the timeline of the events, that around June 5, ten days after the first emissions covered the island, fumes flowed to the east and west, causing a large surge in temperatures and devastating the vegetation.
Poisonous gases
Fouque, continued:- The attention paid to the eruption came principally from the excitement caused by the actions of the poisonous agents. From one narrative, probably a little exaggerated, the men and animals died because they could hardly breath those pestilent vapors.
- "It is evident that the 1808 nuee ardents was more humid and with temperatures below those of 1580...[in those testimonies] the clouds of that first eruption contained 'flames', likely, at least, affirming that they transported incandescent materials, and that the destructive affects were caused by the chlorific power of its natural geochemical properties, quite different from the nuees of 1808. Generally, the identification of the names given by the inhabitants, during two centuries, those singular manifestations are in fact justified for many reasons. In both cases, there was vaporous masses, opaque, filled with powdery materials, in a mass of cloud, that descended the flanks of the mountains along the surface of the soil, and that killed the plants and animals. The existence of "flames" in the 1580 nuee ardente is more suspicious, because, with much difficulty, if we understand gases, whose combustion produces flames, they can travel along, in open air, without becoming inflamed. Admitting also, that there occurred a considerable difference in temperatures of the nuee ardentes in both eruptions, we can not find in this unique fact enough differences to indicate two phenomenons that are absolutely distinct. The chlorific affects described were presented by inexperienced observers: the situation in these places where they were produced, the distance more or less distant from the emission points, the variable rapidity of the volcanic nuee, the climatic conditions particular of the atmosphere in the time of each eruption, and many other things, could still modify considerably the diverse intensity of the actions taken by the heat events. It stands to reason the witnesses of the 1808 eruption..."
- "Similar phenomenons appear near other volcanoes, but maybe in part, some of the nuee ardents traveled better then the two eruptions in São Jorge. I insist much more in my examination, because they appear to furnish a key to a few problems discovered in the exhumations of PompeiiPompeiiThe city of Pompeii is a partially buried Roman town-city near modern Naples in the Italian region of Campania, in the territory of the comune of Pompei. Along with Herculaneum, Pompeii was destroyed and completely buried during a long catastrophic eruption of the volcano Mount Vesuvius spanning...
...The strange situation of the skeletons discovered in the middle of the roads of the Roman volcanic necropole, is very difficult to explain, in the major part of the cases, invoking primarily the analogy of the phenomenons that we observed in the modern eruptions of Vesuvious. A key to the ash showers, although more abundant and laden with humidity, which for example had traveled down the earth and suffocated a man, who was found dead running down a public road, in the company of two daughters. It was necessary to include a delirious gas to kill all three in spontaneous agony...In all the lava that has flowed in the Azores, after the Portuguese arrived, the 1808, of all of them, was the most altering. The musgkee and the lichenLichenLichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s invaded firstly, then the herbaceous vegetation implanted itself in it and in the end the bushes and the trees. Actually, certain portions are transformed in mats, while there, close to the layers of the 1580 lava, they begin to disintegrate.
These suffocating gases, which were probably carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
, were harmful to the population; the thick water-vapor, which condensed in a reddish color, rapidly spread unnoticed through the local vegetation (a mix chloric
Chloric acid
Chloric acid, HClO3, is an oxoacid of chlorine, and the formal precursor of chlorate salts. It is a strong acid and oxidizing agent....
and sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
s) which were expelled as aqueous vapors.
Physically, the events was centered on seven craters, in the area known as Lagoinhas, and its effects were most prominent around the area near the Church of São Mateus. The temple itself was survived by the bell-tower, which became an ex-libris for the island of São Jorge. Even following the eruption, gas emissions continued to be observed from the craters and lava flows.
Reactions
Abandoned by the civil judge, the remaining councilmen, appointed by Royal charter (December 12, 1806), Captain Amaro Teixeira de Sousa, Sargent-major José Soares de Sousa, Capitan João Ignacio da Silveira, and municipal attorney Jorge José Covilhão closed themselves off in the municipal chambers in order to concentrate on the crisis, detailing all their actions in a ledger.Captain-General D. Miguel António de Melo
Miguel António de Melo
D. Miguel António de Melo de Abreu Soares de Brito Barbosa Palha Vasconcelos Guedes served as the fifth captain general of the Azores and the first count of Murça.He was nominated on March 24, 1806 and left for Angra on May 4 of that year....
, realizing the need of the islanders ordered, in a May 18 decree, the free distribution of five moios of corn: recommending that they should plead for "divine mercy" while offering his assistance on the island, if his presence would assist their cause. In a letter dated July 23, the municipal chamber accepted the General's offer of cereal and foodstuffs, but the writer, José Félix Rodrigues Mendes, added:
- "...the greatest gift that your excellency could provide, with the attention of the poverty that remains on this island, is to represent to Our Royal Highness, that he abolish the militia regiment, whose body is formed by a great part of the impoverished of the fires: since the poor do not live on anything but their stipend and, even the more miserable, only appear in their tunics, without even wearing shirts: the occasion is opportune, if your excellency is willing to protect this island, to dignify and make us this the greatest of gifts."
The intent of the request was to free some serf
SERF
A spin exchange relaxation-free magnetometer is a type of magnetometer developed at Princeton University in the early 2000s. SERF magnetometers measure magnetic fields by using lasers to detect the interaction between alkali metal atoms in a vapor and the magnetic field.The name for the technique...
s to assist in the reconstruction, but the Civil Governor and Captain-General, responding in an angry letter, dated October 21, were insulted by the letter's signatories, demanding that those who had signed the document should have their functions suspended (resulting in José Félix Rodrigues Mendes's suspension from the municipal chamber). Out of personal spite, the Captain-General continued that he: "...had, for similar absurdities, run to ground António Sebastião Espínola for these type of ordinary strategies...you deserve that I order your apprehension and have you arrested on my order...!!!"
Afterwards
Over thirty people were killed as a direct consequence of the eruption, while several of the islands of the Azores were affected by ash showers (PicoPico Island
Pico Island , is an island in the Central Group of the Portuguese Azores noted for its eponymous volcano, Ponta do Pico, which is the highest mountain in Portugal, the Azores, and the highest elevation of the Mid-Atlantic Ridge...
, Terceira
Terceira Island
Referred to as the “Ilha Lilás” , Terceira is an island in the Azores archipelago, in the middle of the North Atlantic Ocean. It is one of the larger islands of the archipelago, with a population of 56,000 inhabitants in an area of approximately 396.75 km²...
and São Miguel
São Miguel Island
São Miguel Island , nicknamed "The Green Island", is the largest and most populous island in the Portuguese Azores archipelago. The island covers and has around 140,000 inhabitants, 45,000 of these people located in the largest city in the archipelago: Ponta Delgada.-History:In 1427, São Miguel...
) from June 5 to June 10, or felt continuous earthquakes during the event (as was the case on Faial
Faial Island
Faial Island , also known in English as Fayal, is a Portuguese island of the Central Group of the Azores....
and Pico
Pico Island
Pico Island , is an island in the Central Group of the Portuguese Azores noted for its eponymous volcano, Ponta do Pico, which is the highest mountain in Portugal, the Azores, and the highest elevation of the Mid-Atlantic Ridge...
).
The several earthquakes that occurred during the events motivated officials in Horta
Horta (Azores)
Horta is a single municipality and city in the western part of the Archipealgo of the Azores, encompassing the island of Faial. Horta has a population of about approximately 15,038 people and an area of 173.1 square kilometers. The population density is about 88 persons per square kilometer...
to send personal assistance to the island; in this case a contingent of residents traveled to Velas
Velas
Velas is a municipality in the São Jorge Island, in the Portuguese autonomous region of Azores. The municipality encompasses the western portion of the island, with its municipal seat in the town of Velas on the south coast and divided into six parishes....
in order to offer support and their hospitality to many of the local people affected by the crisis.
The church's parish priest, José António de Barcellos, wrote later (per the writings of João Teixeira Soares), that the event was both an act of God and divine providence, since for years he had requested assistance for the construction of a new parish, and received evasive responses. It was during the governance of Captain-General Francisco de Borja Garção Stockler
Francisco de Borja Garção Stockler
Francisco de Borja Garção Stockler, 1st Baron of Vila da Praia, was a lieutenant general and the eighth Captain General of the Azores, politician, and mathematician. He was one of the pioneers in differential calculus and one of the most notable historians of mathematics in Portugal.-Biography:He...
, after the 1808 eruption, that he was able to raise the costs and through sacrifices, construct the new parish.
The effects of the eruption even persisted to 1810; in that year, three men were asphyxiated when they attempted to clean a salt-water pool along the Urzelina coast (which they had discovered to have been polluted with ash). During excavations made in June 1877, in addition to many ruins, the house once owned by Jorge Soares de Avelar was discovered.