vendredi 23 janvier 2009

Benjamin Franklin was the first to establish the link between volcanic eruptions and climate change

1816, the year without a summer


All thanks to : http://www.centuryinter.net/tjs11/jean/tambora.htm

Benjamin Franklin was the first to establish the link between volcanic eruptions and climate change when he suggested the bitterly cold winter of 1783-84 in Europe was a result of the dust cloud from the massive eruption of Iceland's Mt. Laki in 1783.

Mount Tambora, which is on the Indonesian island of Sumbawa, erupted on April 5, 1815; and resulted in an extremely cold spring and summer in 1816, which became known as the 'year without a summer.'

Its explosion threw so much material into the atmosphere that, as it spread around the world, it changed the climate of the entire planet. In 1816, it snowed in June in the United States and Europe. Crops failed, there was starvation, people lost their farms, and it touched off the wave of emigration that led to the settlement of what is now the American Midwest. In the meantime, hundreds of thousands more starved around the world.

New England and Europe were hit exceptionally hard. Snowfalls and frost occurred in June, July and August and all but the hardiest grains were destroyed. Destruction of the corn crop forced farmers to slaughter their animals. Soup kitchens were opened to feed the hungry. Sea ice migrated across Atlantic shipping lanes, and alpine glaciers advanced down mountain slopes to exceptionally low elevations.

The large amount of sulfuric acid eventually produced in the stratosphere by sulfur-rich gases released during the eruption blocked out solar radiation, resulting in a cooling of Earth's surface for several years after the eruption.

The 1815 eruption of Tambora was one of the largest eruption in historic times. About 150 cubic kilometers of ash were erupted (about 150 times more than the 1980 eruption of Mount St. Helens). Ash fell as far as 800 miles (1,300 km) from the volcano. In central Java and Kalimantan, 550 miles (900 km) from the eruption, one centimeter of ash fell.

The eruption column reached a height of about 28 miles (44 km). The collapse of the eruption column produced numerous pyroclastic flows. As these hot pyroclastic flows reached the ocean where they caused additional explosions. During these explosions, most of the fine-fraction of the ash was removed.

The eruption formed a caldera. An estimated 92,000 people were killed by the eruption. About 10,000 direct deaths were caused by bomb impacts, tephra fall, and pyroclastic flows. An estimated 82,000 were killed indirectly by the eruption by starvation, disease, and hunger.

See Tambora, Sumbawa, Indonesia

Tambora is famous for giving birth to Mary Shelley's Gothic novel ''Frankenstein.''

The late frosts of that cold, dark 1816 summer destroyed crops across Europe and kept Shelley and her husband Percy holed up on the shores of Lake Geneva at the house of Lord Byron, who suggested a ghost story writing contest to amuse them.

Percy Shelley and Lord Byron soon abandoned their efforts, but Mary persisted, creating a mixture of Gothic horror and science fiction which has influenced our views of science to this day.

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From Brethren Life: Frontier

"This was a very bad year, everywhere, but especially on the frontier. A popular expression was: "1816 and froze to death!" It got cold at night all summer and crops would not grow, There was a killing frost at least once during every month. June 5 and 6, the temperature dropped to below 40, then on the 7th it snowed. There were killing frosts all three nights. By June 11th, the corn was withered and dead in the field. It was replanted, then in July the new stand was killed by another killing frost.

On August 20, 1816, the temperature again plunged and any remaining crops were destroyed. Sept. 27 saw the start of winter with another killing frost. ... Snows started early in October, and stayed on the ground until April 1817. The snows were two feet deep with a terrible ice crust on top. Many survived only because the deer were trapped by the snows and ice and could not escape the hunters.

Following that winter, deer were so scarce that they could not be depended on as a source for meat, nor was the common deerskin britches and jacket any more available ..."

ARTICLE from The Decatur County Journal, June 9, l892

``The year without a summer, l8l6, is now being quite generally recalled.

According to the records, January and February of that year were warm and spring like. March was cold and stormy.

Vegetation had gotten well along in April when real winter set in. Sleet and snow fell on seventeen different days in May.

In June there was either frost or snow every night but three. The snow was five inches deep for several days in succession in the interior of New York and from ten inches to three feet in Vermont and Maine.

July was cold and frosty, ice formed as thick as window panes in every one of the New England States.

August was still worse; ice formed nearly an inch in thickness, and killed nearly every green thing in the United States and in Europe.

In the spring of l8l7, corn, which had been kept over from the crop of l8l5, sold for from $5 to $l0 a bushel, the buyers purchasing for seed ... ''

CAHOKIA - World Heritage

From Wikipedia

Cahokia is the site of an ancient Native American city (650-1400 CE) near Collinsville,Illinois in the American Bottom floodplain, across the Mississippi River from St. Louis, Missouri. The 2,200-acre (8.9 km2) site includes at least 109 man-made earthen mounds. Cahokia Mounds is the largest archaeological site related to the Mississippian culture, which developed advanced societies in eastern North America centuries before the arrival of Europeans. [1]. It is a designated site for state protection, a National Historic Landmark, and a World Heritage Site.

Cahokia was the most important center for the peoples known today as Mississippians. Their settlements ranged across what is now theMidwestEastern, and Southeastern United States. Cahokia maintained trade links with communities as far away as the Great Lakes to the north and the Gulf Coast to the south. Pottery and stone tools in the Cahokian style were found at the Silvernale site near Red Wing, Minnesota.

At the high point of its development, Cahokia was the largest urban center north of the great Mesoamerican cities in Mexico. Although it was home to only about 1,000 people before ca. 1050, its population grew explosively after that date. Archaeologists estimate the city's population at between 8,000 and 40,000 at its peak, with more people living in outlying farming villages that supplied the main urban center.

If the highest population estimates are correct, Cahokia was larger than any subsequent city in the United States until about 1800, whenPhiladelphia's population grew beyond 40,000.



Cahokia Mounds State Historic Site*
UNESCO World Heritage Site

Monk's Mound is the largest earthen structure at Cahokia.

Cahokia was settled around 650 CE during the Late Woodland period. Mound building did not begin until about 1050 CE, at the beginning of the Mississippian cultural period. The inhabitants left no written records beyond symbols on pottery, shell, copper, wood, and stone.[3]. The city's original name is unknown.

The name "Cahokia" also refers to an unrelated clan of Illiniwek people living in the area when the first French explorers arrived in the 1600s, long after Cahokia was abandoned. The living descendants of the Cahokia people associated with the Mound site are unknown, although many Native American groups are plausible.





The Travel Channel has called it the "world's largest pyramid."


Cahokia was abandoned a century or more before Europeans arrived in North America in the early 1500s. Scholars have proposed environmental factors such as over-hunting and deforestation as explanations. Another possible cause is invasion by outside peoples, though the only evidence of warfare found so far is the wooden stockade and watchtowers that enclosed Cahokia's main ceremonial precinct. Due to the lack of other evidence for warfare, the palisade appears to have been more for ritual than military purposes. Diseases transmitted among the large, dense urban population are another possible cause of decline. Many recent theories propose conquest induced political collapse as the primary reason for Cahokia’s abandonment.[12]

[edit]See also

De - Tribune de Geneve

Merci aux hommes libres

http://hommelibre.blog.tdg.ch/archive/2008/11/13/hemisphere-nord-la-grande-famine-de-1816-l-annee-sans-ete.html

13 novembre 2008

Hémisphère nord: la grande famine de 1816 - l’année sans été

L’année 1816 fut l’année sans été en Europe et aux Etats-Unis, et même jusqu’en Chine. C’est ainsi que les historiens ont nommé cette année catastrophique. L’Europe connu des températures inférieures à 0 degré pendant l’été, des pluies glaciales, et toutes les récoltes furent détruites. Que s’est-il passé?


Tambora1.pngEn 1812 et 1814, des volcans des Caraïbes et des Philippines avaient été très actifs, laissant dans l’atmosphère des tonnes de poussière. En 1815, un volcan d’Indonésie, le Tambora, a explosé, un peu à la manière du Krakatoa en 1883. L’explosion du Tambora fut décrite par des témoins et transcrite par les chroniqueurs de l’époque.

“Le 5 avril 1815 eut lieu une première éruption donnant une colonne éruptive de 33 km de hauteur et qui dura 33 heures. Le paroxysme de l'éruption eut lieu 5 jours plus tard, le 10 avril. Vers 10h du matin, une colonne éruptive de 44 km de haut monta dans le ciel, mais l'éruption dura seulement 3h. Vers 7h de l'après-midi, l'activité du volcan augmenta, suivi une heure plus tard d'une pluie de ponce sur le village de Sanggar, 30 km à l'est. Le volcan à ce moment était alors surmonté d'après les témoins de trois « colonnes de flammes », en fait trois colonnes éruptives. La chute de pierres ponces dura jusqu'à 10h du soir, lorsque le village de Sanggar fut ravagé par une onde de choc. Vers ce moment, toujours d'après les témoins, les trois colonnes fusionnèrent et la montagne ne fut plus qu'une masse de « feu liquide ».”

Le volcan tua directement 11’000 personnes et le tsunami qui suivi environ 50’000. La poussière du Tambora, ajoutée à celle des autres volcan, fit un nuage sur l’hémisphère nord pendant presque deux ans. Le soleil étant voilé, voire absent pendant toute l’année 1816, la température se refroidit dramatiquement.

“En mai 1816, le gel détruisit la plupart des récoltes qui avaient été plantées et en juin deux grands blizzards dans l'Est du Canada et en Nouvelle-Angleterre entraînèrent de nombreuses morts. C'est presque un pied de neige qui fut observé dans la ville de Québec au début de juin. En juillet et août, on vit de la glace sur les lacs et les rivières aussi loin vers le sud qu'en Pennsylvanie. Des différences rapides et extrêmes de température étaient habituelles et des températures normales ou proches de la normale en été, allant jusqu'à 35 °C, pouvaient tomber au-dessous de zéro en quelques heures.”

Les conséquences humaines furent particulièrement graves:

“L'Europe, qui n'était pas encore rétablie des guerres napoléoniennes, connut une crise alimentaire. Des émeutes de subsistance éclatèrent en Grande-Bretagne et en France et les magasins de grains étaient pillés. La violence fut la pire en Suisse, pays privé d'accès à la mer, où la famine força le gouvernement à déclarer l'état d'urgence. Des tempêtes d'une rare violence, une pluviosité anormale avec débordement des grands fleuves d'Europe (y compris le Rhin) sont attribuées à l'événement, comme l'était le gel survenu en août 1816. Un documentaire de la BBC réalisé en Suisse estimait que les taux de mortalité en 1816 étaient cette année deux fois supérieurs à la moyenne avec au total deux cent mille morts.”

Les populations en étaient souvent réduites à manger des racines, quand celles-ci n’étaient pas gelées. Les couchers de soleils avaient pris des Turner.jpgteintes psychédéliques, et le peintre Turner en témoigne dans certains tableaux de cette époque. En fait tout l’hémisphère nord fut atteint:

“L'éruption du Tambora donna aussi en Hongrie un exemple de neige marron. L'Italie connut quelque chose d'analogue, avec de la neige rouge qui tomba tout au long de l'année. On croit que la cause en était la cendre volcanique contenue dans l'atmosphère.

En Chine, les températures exceptionnellement basses de l'été et des trombes d'eau furent désastreuses pour la production de riz dans la province du Yunnan au Sud-Ouest, avec comme résultat une famine générale. Fort Shuangcheng, aujourd'hui dans la province de Heilongjiang, signala que des champs avaient été ravagés par le gel et qu'en conséquence les conscrits désertaient. Des chutes de neige en été se produisirent en différents endroits dans les provinces de Jiangxi et d'Anhui, toutes les deux dans le Sud du pays. À Formose, pourtant sous un climat tropical, on vit de la neige à Hsinchu et à Miaoli, et du gel à Changhua.”


Sources: http://fr.wikipedia.org/wiki/Ann%C3%A9e_sans_%C3%A9t%C3%A9

The period 1812-1817 was one of exceptional volcanic activity

1816 - The Year without a Summer
http://www.dandantheweatherman.com/Bereklauw/yearnosummer.html

Introduction


The period 1812-1817 was one of exceptional volcanic activity, and the sheer volume of volcanic dust pumped into the atmosphere by these volcanic eruptions caused a general, temporary cooling in the earth’s climate around this time.

This temporary climatic cooling peaked during the summer of 1816 was the peak of this cooling and the reason the peak fell in the summer of 1816 is almost certainly die to the eruption of the Tamboro volcano east of Java in April 1815 (believed to be one of the most explosive eruptions of the last 10,000 years).

At the time sunspots were blamed for the unseasonable weather (Laskin 1996).

Anyway, this eruption put more than 150 million tonnes of dust in the atmosphere which gradually spread around the globe acting as a veil reflecting incoming solar radiation back into space and cooling the earth (temporarily) which in turn caused a change in the world’s, and in particular the northern hemisphere’s, weather patterns.

Some dust from volcanic eruptions in the West Indies in 1812 and Philippines in 1814 was also probably still the atmosphere (Lamb 1995) and this will have helped the global cooling process too.

So if Tamboro erupted in 1815 why wasn’t the summer of 1815 rather than the summer of 1816 the year without a summer? Well, the answer is that there is a time lag between a volcanic eruption and a change in weather patterns caused by the length of time needed for stratospheric winds to distribute the volcanic dust particles around the world.

It should at this stage be pointed out that not all volcanic eruptions affect the climate - whether an eruption will affect the climate or not depends on how powerful the eruption is and what part of the atmosphere the dust from the eruption reaches. When volcanoes erupt lots of gas and dust is injected into the atmosphere. Depending on how the volcano erupts (eg vertically or horizontally) and where the volcano is a large eruption can have a cooling effect on the atmosphere which can last for 1-3 years or so. The dust and gases need to reach the Stratosphere (more than 10km above sea level) where winds at that level in the atmosphere can blow the dust and gas around the world. The dust and gas then reflect energy from the sun which would otherwise reach the earth back into space this cooling the earth and altering its weather patterns. This sort of thing has happened from time to time through the earth’s history and most recently in the early 1990’s when the eruption of Mount Pinatubo in the Philippines in 1991 cooled global temperatures in 1992 by around half a degree.

Now, here some of the highlights of the year without a summer:

Canada
Between May and September southern Quebec was affected by a series of cold waves which killed crop and led to near famine conditions in some parts. During one such cold spell between June 6th and 10th 30-36cms snow lay on the ground in Quebec City. Meanwhile on June 6th and 8th it snowed in Montreal (Neil Davids 1976). Sub-zero temperatures during June blackened crops and froze ponds killing wildfowl.

Some mornings in July and August were decidedly chilly and probably frosty, whilst hard frosts on 11th, 12th and 27th September ended the already shortened growing season.

Northeastern USA
In New England the summer of 1816 included some early June snow, cold nights in both July and August, for example the widespread frost at low level sites around New England on the 8-9th July and the damaging frosts on the 22nd August from interior New England right the way south into North Carolina (Ludlum 1989). There were droughts too and finally killing frosts in September, such as that of the 27th in New England (Ludlum 1976, 1989). This all led to crop failures and food shortages and helped stimulate a move westwards the following year. In both Connecticut and parts of New York State frosts after April are rare, but in 1816 frosts were recorded every month of the year (Lamb 1816, Neil Davids).

Summer temperatures were between slightly below average and 3-5 degrees below average, depending on which source you choose to believe. The most severe cold snap came in early June and killed the vegetable crop in parts of New England, ruining some farmers. This, and a couple of other cold snaps, each just a few days long, has made the summer of 1816 notorious and infamous, hadly surprising given the far reaching consequences of the unseasonable weather. The worst of the weather and of the effects of the poor weather was in northern New England. However, conditions during the summer were also, well, summer-like at times. For example, a late June heatwave saw temperatures top 32C between the 22nd and 24th June and temperatures were near normal for much of the first two-thirds of August (Ludlum 1985). It should also be pointed out that since 1816 it has been just as cold or even colder in each of the summer months but never in consecutive months.

The most notorious part of the infamous summer of '16 was the cold snap in early June. Juen began promising enough and on the 5th temperatures in New England climbed into the low 30's Celsius, for example Salem, Mass., reached 32C. However, during the afternoon of the 5th thundery showers broke out over New England and later in the day a cold front swept across the region, dragging cold air down from Canada in its wake. The next day, the 6th, was much colder. Some places were as much as 27 degrees colder than the day before (Ludlum 1989), and in parts of Vermont and in Boston temperatures reached little more than 7C (Ludlum 1985, Laskin 1996). Conditions turned colder during the next 2 or 3 days and precipitation that fell became increasingly wintry in nature. On the 7th snow fell over the northern highlands of New England, snow flurries fell in parts of Connecticut and Massachusetts (Ludlum 1976), in Salem and Boston for example, and away from the coast, snow fell in June as far south as 42 degrees north (Lamb 1995). Near Danville, Vermont snowdrifts just over 50cms high were reported (Ludlum 1985). Contemporary reports spoke of prolonged falls of snow, snow settling and lying for a couple of days and very windy weather at times (Ludlum 1985). However, by the 10th and 11th conditions began to improve, although mornings were still frosty.

By the 12th June 1816 temperatures were rather more normal and in the 20's Celsius, and there they stayed until the 22nd to the 24th when something of a heatwave developed; during these 3 days temperatures around New England widely topped 32C. On the 23rd a high of 37C was recorded at Waltham, Massachusetts (Ludlum 1976) whilst on 24th June Salem, Massachusettes also reached 37C (Ludlum 1989). The Boston area also reached the high 30's Celsius during this time (Ludlum 1985).

July 1816 was notable for a lack of warm nights, which, it turns out, are necessary in allowing corn to grow and ripen. Some of the coldest nights were on the 8th and 9th when a light ground frost affected some areas, such as the Upper Connecticut Valley and at Middlebury, Windsor and Williamstown in Vermont (Ludlum 1985). July 1816 was also a very dry month and drought began to affect the harvest in some parts of New England. Moving into August, temperatures were normal for the first two-thirds of the month, and peaked in the low 30's Celsius on the 18th and 19th, whilst connditions remained dry. The passage of an active cold front on the 20th led to a cooling down and a couple of spells of frosty nights during the last third of the month which wiped out crops in some northern parts of New England (Ludlum 1985). Contemporary reports mentioned snow covered mountains in August and the dry, cool conditions of late August persisted through September which ended with a series of crop killing frosts (Ludlum 1985).

Europe
Europe was worse affected than the USA (possibly something to do with the relative sizes of population rather than weather conditions themselves). Either way, cold weather and rain caused crop failures and famine.

During the summer the northern hemisphere's most unsettled weather is usually concentrated in the sub-Arctic region. However, during the summer of 1816 some of the northern hemisphere most unsettled weather was to be found in an area extending from Newfoundland eastwards across the Atlantic Ocean and England into the southern Baltic.

With this in mind it's perhaps to suprise to find that it rained on 142 out of 153 days during the May-September period in Ireland. In England the Central England Temperature Series value for the summer of 1816 is 13.37C, the third coldest summer on record (records began in 1659) behind those of 1725 (13.17C) and 1695 (13.1C) which occured during the Little Ice Age. A few Mays, plenty of Septembers and a couple of Octobers in England have been warmer than any of the three summer months in the summer of 1816. Low temperatures and prolonged rain caused crop failures in some western parts of Britain whilst to the south-east parts of Switzerland experience famine due to crop failures (Lamb 1995).

Away from Britain, there were food riots in France and Switzerland and at least 200,000 died from hunger and a typhus epidemic in Europe whilst in Germany there was a sharp peak in rye prices in 1816 and 1817 and around Europe wheat prices also rose at that time.

Meanwhile, near Iceland sea ice persisted into June. The unusual weather patterns of the summer of 1816 have also been blamed for causing or adding to the severity of a number of plagues and epidemics, including the 1816-1819 European typhus epidemic which was among the severest ever, a plague which affected south-eastern Europe and the Mediterranean between 1816 and 1819 (Lamb 1995).

So far we’ve focused on where weather patterns were negatively altered, but whenever there are unusually cold and wet weather patterns in one part of the world the opposite weather pattern will occur somewhere else in the world to compensate. And so it was in the summer of 1816 when Ukraine had a hot summer and northern Scotland and the Shetland Islands were fine (Lamb 1995).

Asia
The Asian summer monsoon didn’t go unaffected; the far east and Korea had some heavy rains whilst summer rainfall over India was concentrated in the south of the country and a huge cholrea epidemic which began in 1816-17 may also have been linked to the adverse weather conditions during the summer of 1816 (Lamb 1995).

Consequences and Final Remarks
The near destruction of the harvest in New England led to the first mass migration out of New England to the mid-west which in turn led to a shift of farming away from eastern USA. In other words, a few days of bad weather one summer nearly 200 years changed farming in the USA for ever! The summer of 1816 and the fact that in England other summers at this time were cooler and wetter than in the 18th century may have led to the practice of irrigation being abandoned, particularly from the 1820's onwards (Lamb 1995). In the far east climatic cooling in the early 19th century led to crop failures in the Yantze Valley in China and in parts of Japan. Globally, the period 1820-1850 was one of social upheaval, international migration, disease epidemics and various crises and some writers have suggested that this might not be entirely unconnected to the climatic events during the 1810's.

Some of these consequences are perhaps not directly attributable to the summer of 1816, but certainly to the general climate of the time, but one definite consequence of the summer of 1816 is that the bad summer weather over central Europe inspired Mary Shelley to write her novel Frankenstein.

References/Sources
CHANG, G. (1999): 1816: The Year Without a Summer, www.exn.ca/volcanoes/weather.cfm
LAMB, H. H. (1995): Climate, History and the Modern World, Routledge, p.433
LASKIN, D. (1996): Braving the Elements, The Stormy History of American Weather, Anchor Books, p.241
LUDLUM, D. (1976): The Country Journal New England Weather Book, Houghton Mifflin Company, p.147
LUDLUM, D. (1985): The Vermont Weather Book, The Vermont Historical Meteorological Society, p.300
LUDLUM, D. (1989): The American Weather Book, The American Meteorological Society, p.296
NEIL DAVIDS, T. (1976): 1816 The Year Without a Summer, www.gi.alaska.edu/ScienceForum/ASF0/098.html
PHILLIPS, D. (1990): The Climates of Canada, Minister of Supply and Services Canada, p.176

Many of these books are out of print. However, they can be bought from second hand book dealers. The best place I've found to buy old books on the 'net is Abebooks.com, who I can thoroughly recommend. The search engine is dead easy to use and I've never had a purchase that's gone wrong!

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Dan Suri, 27 January 2002

1816 ... the year without summer

Solar, Ocean, Windflows leading to a short or long term Cold are vulnerable to ashes from Volcanoes.

Here what hapen in 1816..

From Wikipedia
The Year Without a Summer (also known as the Poverty Year, and the Year There Was No Summer) was 1816, in which severe summer climate abnormalities destroyed crops in Northern Europe, the American Northeast and eastern Canada.[1][2] Historian John D. Post has called this "the last great subsistence crisis in the Western world".[3] It appears to have been caused by a volcanic winter.

In is in this summer of 1916 that in Swirtzerland that few authors created personnas well known today, that is Frankenstein and Dracula.

I have been devoted to Individual, Community, City, Regions and Inter-regional preparedness in face of a major crisis, My Leitmotiv has been and still is << Lets reduce morbidity and mortality .

My experience has shown over and over that it makes a difference.

www.msf.org