Editing Mount Tambora (section)

=== 1815 eruption ===
[[File:1815 tambora explosion.png|upright=1.75|thumb|Estimated depth of volcanic ashfall during the 1815 eruption—the outermost region (1&nbsp;cm) reached [[Borneo]] and the [[Sulawesi]] islands]]
{{Main|1815 eruption of Mount Tambora}}

==== Chronology of the eruption ====
Before 1815, Mount Tambora had been [[dormant volcano|dormant]] for several centuries, as hydrous [[magma]] cooled gradually in a closed magma chamber.<ref name="Foden1986"/> Inside the chamber, at depths of {{convert|1.5|to|4.5|km|mi|1}}, cooling and partial [[crystallization]] of the magma [[Volcanic gas#Magmatic gases and high-temperature volcanic gases|exsolved]] high-pressure [[magmatic water|magmatic fluid]]. Overpressure of the chamber of about {{convert|4000|to|5000|bar|psi}} was generated as temperatures ranged from {{convert|700|to|850|C|F|sigfig=2}}.<ref name="Foden1986"/> In 1812, the crater began to rumble and generated a dark cloud.<ref name="Stothers1984">{{cite journal |date=1984 |last=Stothers |first=Richard B. |title=The Great Tambora Eruption in 1815 and Its Aftermath |journal=Science |volume=224 |issue=4654 |pages=1191–1198 |doi=10.1126/science.224.4654.1191 |pmid=17819476 |bibcode=1984Sci...224.1191S |s2cid=23649251}}</ref>

A moderate-sized eruption on 5 April 1815 was followed by thunderous detonation sounds that could be heard in [[Ternate]] on the [[Molucca|Molucca Islands]], {{convert|1400|km|mi}} from Mount Tambora. On the morning of 6 April 1815, [[volcanic ash]] began to fall in [[East Java]], with faint detonation sounds lasting until 10 April.<ref name="Stothers1984"/>
What was first thought to be the sound of firing guns was heard on 10 and 11 April on [[Sumatra]] island (more than {{convert|2600|km|mi}} away),<ref name="Raffles1830">{{cite book |date=1830 |last=Raffles |first=S. |title=Memoir of the life and public services of Sir Thomas Stamford Raffles, F.R.S. &c., particularly in the government of Java 1811–1816, and of Bencoolen and its dependencies 1817–1824: with details of the commerce and resources of the eastern archipelago, and selections from his correspondence |url=http://www.sabrizain.org/malaya/library/memraffles1.pdf |location=London |publisher=John Murray |access-date=2 August 2018 |archive-date=2 August 2018 |archive-url=https://web.archive.org/web/20180802223556/http://www.sabrizain.org/malaya/library/memraffles1.pdf |url-status=live }} Cited by Oppenheimer (2003)</ref> and possibly over {{convert|3350|km|mi}} away in [[Thailand]] and [[Laos]].<ref name=":1">{{Cite journal |last=Goldrick |first=Richard |title=Tambora's Rumblings in The Annals of Lang Xang |journal=}}</ref>
 
The eruptions intensified at about 7:00&nbsp;p.m. on the 10th.<ref name="Stothers1984"/> Three plumes rose and merged.<ref name="Raffles1830"/> Pieces of [[pumice]] of up to {{convert|20|cm|in}} in diameter rained down at approximately 8&nbsp;p.m., followed by ash at around 9–10&nbsp;p.m. The [[eruption column]] collapsed, producing hot [[pyroclastic flow]]s that cascaded down the mountain and towards the sea on all sides of the [[peninsula]], wiping out the village of Tambora. Loud explosions were heard until the next evening, 11 April. The veil of ash spread as far as [[West Java]] and [[South Sulawesi]], while a "nitrous odor" was noticeable in [[Jakarta|Batavia]]. The heavy [[tephra]]-tinged rain did not recede until 17 April.<ref name="Stothers1984"/> Analysis of various sites on Mount Tambora using ground-penetrating radar has revealed alternations of pumice and ash deposits covered by the pyroclastic surge and flow sediments that vary in thickness regionally.<ref name="Abrams2007">{{cite journal |date=2007 |last1=Abrams |first1=Lewis J. |last2=Sigurdsson |first2=Haraldur |title=Characterization of pyroclastic fall and flow deposits from the 1815 eruption of Tambora volcano, Indonesia using ground-penetrating radar |url=http://people.uncw.edu/abramsl/Abrams-Sigurdsson-volgeo-07.pdf |journal=Journal of Volcanology and Geothermal Research |volume=161 |issue=4 |pages=352–361 |access-date=2 August 2018 |doi=10.1016/j.jvolgeores.2006.11.008 |bibcode=2007JVGR..161..352A |archive-date=4 August 2020 |archive-url=https://web.archive.org/web/20200804061055/http://people.uncw.edu/abramsl/Abrams-Sigurdsson-volgeo-07.pdf |url-status=live }}</ref>

The eruption is estimated to have had a [[Volcanic Explosivity Index]] of 7.<ref name="Briffa1998">{{cite journal |year=1998 |last1=Briffa |first1=K.R. |last2=Jones |first2=P.D. |last3=Schweingruber |first3=F.H. |last4=Osborn |first4=T.J. |title=Influence of volcanic eruptions on Northern Hemisphere summer temperature over the past 600 years |journal=Nature |volume=393 |issue=6684 |pages=450–455 |doi=10.1038/30943 |bibcode=1998Natur.393..450B |s2cid=4392636}}</ref> It had 4–10 times the energy of the [[1883 eruption of Krakatoa|1883 Krakatoa eruption]].<ref>[https://www.smithsonianmag.com/history/blast-from-the-past-65102374/''Blast from the Past''] {{Webarchive|url=https://web.archive.org/web/20220315104117/https://www.smithsonianmag.com/history/blast-from-the-past-65102374/ |date=15 March 2022 }}; article; [July, 2002]; By Robert Evans; Smithsonian Magazine, online; accessed September 10, 2020</ref> An estimated {{convert|100|km3}} of pyroclastic [[trachyandesite]] was ejected, weighing approximately [[Orders of magnitude (mass)|1.4×10<sup>14</sup>&nbsp;kg]].<ref name="Oppenheimer2003"/> This has left a caldera measuring {{convert|6|to|7|km|mi}} across and {{convert|600|to|700|m|ft}} deep.<ref name="Stothers1984"/> The density of fallen ash in [[Makassar]] was 636&nbsp;kg/m<sup>3</sup>.<ref name="Stothers2004">{{cite journal |date=2004 |last=Stothers |first=Richard B. |title=Density of fallen ash after the eruption of Tambora in 1815 |journal=Journal of Volcanology and Geothermal Research |volume=134 |issue=4 |pages=343–345 |doi=10.1016/j.jvolgeores.2004.03.010 |bibcode=2004JVGR..134..343S}}</ref> Before the explosion, Mount Tambora was approximately {{convert|4300|m|ft}} high,<ref name="Stothers1984"/> one of the tallest peaks in the Indonesian archipelago. After the eruption of 1815, the maximum elevation was reduced to {{convert|2851|m|ft}}.<ref name="Monk">{{cite book |date=1996 |last1=Monk |first1=K.A. |last2=Fretes |first2=Y. |last3=Reksodiharjo-Lilley |first3=G. |title=The Ecology of Nusa Tenggara and Maluku |publisher=Periplus Editions Ltd. |location=Hong Kong |page=60 |isbn=978-962-593-076-3}}</ref>

The 1815 Tambora eruption is the largest and most devastating observed eruption in recorded history; a comparison with other major eruptions is listed below.<ref name="Oppenheimer2003"/><ref name="Stothers1984"/><ref name="cao">{{cite journal |date=2012 |last1=Cao |first1=S. |last2=Li |first2=Y. |last3=Yang |first3=B. |title=Mt. Tambora, Climatic Changes, and China's Decline in the Nineteenth Century |journal=Journal of World History |volume=23 |issue=3 |pages=587–607 |doi=10.1353/jwh.2012.0066 |s2cid=145137831}}</ref> The explosion was heard {{convert|2600|km|mi}} or  {{convert|3350|km|mi}}  away, and ash deposits were registered at a distance of at least {{convert|1300|km|mi}}. A pitch of darkness was observed as far away as {{convert|600|km|mi}} from the mountain summit for up to two days.<ref name="Stothers1984"/> Pyroclastic flows spread to distances of about {{convert|20|km|mi}} from the summit and an estimated 9.3–11.8 × 10<sup>13</sup> g of stratospheric sulfate aerosols were generated by the eruption.<ref>{{cite journal |date=1 October 2004 |last1=Self |first1=S. |last2=Gertisser |first2=R. |last3=Thordarson |first3=T. |last4=Rampino |first4=M.R. |last5=Wolff |first5=J.A. |title=Magma volume, volatile emissions, and stratospheric aerosols from the 1815 eruption of Tambora |journal=Geophysical Research Letters |volume=31 |issue=20 |pages=L20608 |doi=10.1029/2004GL020925 |url=https://www.pure.ed.ac.uk/ws/files/11410401/Magma.pdf |bibcode=2004GeoRL..3120608S |hdl=20.500.11820/6925218f-d09e-4f9d-9f2e-3ab8419b223f |s2cid=56290102 |hdl-access=free |access-date=30 June 2019 |archive-date=26 April 2019 |archive-url=https://web.archive.org/web/20190426135239/https://www.pure.ed.ac.uk/ws/files/11410401/Magma.pdf |url-status=live }}</ref>

==== Aftermath ====
The island's entire vegetation was destroyed as uprooted trees, mixed with pumice ash, washed into the sea and formed rafts of up to {{convert|5|km|mi}} across.<ref name="Stothers1984"/> One [[pumice raft]] was found in the [[Indian Ocean]], near [[Calcutta]], on 1 and 3 October 1815.<ref name="Oppenheimer2003"/> Clouds of thick ash still covered the summit on 23 April. Explosions ceased on 15 July, although smoke emissions were still observed as late as 23 August. Flames and rumbling aftershocks were reported in August 1819, four years after the event.

{{Quote box|width=30em|align=right|quote=On my trip towards the western part of the island, I passed through nearly the whole of [[Dompu|Dompo]] and a considerable part of Bima. The extreme misery to which the inhabitants have been reduced is shocking to behold. There were still on the road side the remains of several corpses, and the marks of where many others had been interred: the villages almost entirely deserted and the houses fallen down, the surviving inhabitants having dispersed in search of food.<br />...<br />Since the eruption, a violent diarrhoea has prevailed in Bima, Dompo, and Sang’ir, which has carried off a great number of people. It is supposed by the natives to have been caused by drinking water which has been impregnated with ashes; and horses have also died, in great numbers, from a similar complaint.|salign=right |source=—Lt. Philips, ordered by Sir [[Stamford Raffles]] to go to [[Sumbawa]]<ref name="Raffles1830"/>}}

A moderate [[tsunami]] struck the shores of various islands in the Indonesian archipelago on 10 April, with waves reaching {{convert|4|m|ft}} in Sanggar at around 10&nbsp;p.m. A tsunami causing waves of {{convert|1|to|2|m|ft}} was reported in Besuki, [[East Java]] before midnight and another exceeded {{convert|2|m|ft}} in the [[Molucca|Molucca Islands]].<ref name="Stothers1984"/> The [[eruption column]] reached the [[stratosphere]] at an altitude of more than {{convert|43|km|ft}}.<ref name="Oppenheimer2003"/> Coarser ash particles fell one to two weeks after the eruptions, while finer particles stayed in the atmosphere for months to years at an altitude of {{convert|10|to|30|km|ft}}.<ref name="Stothers1984"/> There are various estimates of the volume of ash emitted: a recent study estimates a [[dense-rock equivalent]] volume for the ash of {{convert|23|±|3|km3}} and a dense-rock equivalent volume of {{convert|18|±|6|km3}} for the pyroclastic flows.<ref>{{cite journal |last1=Kandlbauer |first1=J. |last2=Sparks |first2=R.S.J. |title=New estimates of the 1815 Tambora eruption volume |journal=Journal of Volcanology and Geothermal Research |date=October 2014 |volume=286 |pages=93–100 |doi=10.1016/j.jvolgeores.2014.08.020 |bibcode=2014JVGR..286...93K}}</ref> Longitudinal winds spread these fine particles around the globe, creating optical phenomena. Between 28 June and 2 July, and between 3 September and 7 October 1815, prolonged and brilliantly coloured sunsets and twilights were frequently seen in London. Most commonly, pink or purple colours appeared above the horizon at twilight and orange or red near the horizon.<ref name="Stothers1984"/>

==== Fatalities ====
The number of fatalities has been estimated by various sources since the 19th century. Swiss botanist [[Heinrich Zollinger]] travelled to Sumbawa in 1847 and recollected witness accounts about the 1815 eruption of Tambora. In 1855, he published estimates of directly killed people at 10,100, mostly from pyroclastic flows. A further 37,825 died from starvation on [[Sumbawa]] island.
<ref name="Haeseler2016">{{cite web |date=2016 |last=Haeseler |first=Susanne |title=Der Ausbruch des Vulkans Tambora in Indonesien im Jahr 1815 und seine weltweiten Folgen, insbesondere das "Jahr ohne Sommer" 1816 |url=https://www.dwd.de/DE/leistungen/besondereereignisse/verschiedenes/20170727_tambora_1816_global.pdf |publisher=Deutscher Wetterdienst |pages=1–18 |language=de |access-date=2 August 2018 |archive-date=16 February 2020 |archive-url=https://web.archive.org/web/20200216081313/https://www.dwd.de/DE/leistungen/besondereereignisse/verschiedenes/20170727_tambora_1816_global.pdf |url-status=live }}</ref> On [[Lombok]], another 10,000 died from disease and hunger.<ref name="Zollinger1855">Zollinger (1855): ''Besteigung des Vulkans Tamboro auf der Insel Sumbawa und Schiderung der Eruption desselben im Jahren 1815'', Winterthur: Zurcher and Fürber, Wurster and Co., cited by Oppenheimer (2003).</ref> Petroeschevsky (1949) estimated that about 48,000 and 44,000 people were killed on Sumbawa and Lombok, respectively.<ref name="Petroeschevsky1949">{{cite journal |last=Petroeschevsky |first=W.A. |date=1949 |title=A contribution to the knowledge of the Gunung Tambora (Sumbawa) |journal=Tijdschrift van het Koninklijk Nederlandsch Aardrijkskundig Genootschap |volume=2 |issue=66 |pages=688–703}}, cited by Oppenheimer (2003).</ref> Several authors have used Petroeschevsky's figures, such as Stothers (1984), who estimated 88,000 deaths in total.<ref name="Stothers1984"/> Tanguy et al. (1998) considered Petroeschevsky's figures based on untraceable sources, so developed an estimate based solely on two primary sources: Zollinger, who spent several months on Sumbawa after the eruption, and the notes of [[Sir Stamford Raffles]],<ref name="Raffles1830"/> Governor-General of the Dutch East Indies during the event. Tanguy pointed out that there may have been additional victims on [[Bali]] and [[East Java]] because of famine and disease, and estimated 11,000 deaths from direct volcanic action and 49,000 from post-eruption famine and epidemics.<ref name="Tanguy1998">{{cite journal |date=1998 |last1=Tanguy |first1=J.-C. |last2=Scarth |first2=A. |last3=Ribière |first3=C. |last4=Tjetjep |first4=W. S. |title=Victims from volcanic eruptions: a revised database |journal=Bulletin of Volcanology |pages=137–144 |volume=60 |issue=2 |doi=10.1007/s004450050222 |bibcode=1998BVol...60..137T |s2cid=129683922}}</ref> Oppenheimer (2003) estimated at least 71,000 deaths,<ref name="Oppenheimer2003"/> and numbers as high as 117,000 have been proposed.<ref name="cao"/>

{| class="wikitable sortable"
|+ <big>Comparison of major volcanic eruptions</big>
|-
! Volcano !! Location !! Year !! Column<br />height (km) !! &nbsp;[[VEI]]&nbsp; !! N. hemisphere<br />summer anomaly (°C) !! Fatalities
|-
| [[Hatepe eruption|Taupō Volcano]] || {{NZL}} || 181 || style="text-align:center;" | 51 || style="text-align:center;" | 7 || style="text-align:center;" | ? || unlikely
|-
| [[946 eruption of Paektu Mountain|Paektu Mountain]] || {{DPRK}} || 946 || style="text-align:center;" | 25 || style="text-align:center;" | 7 || style="text-align:center;" | ? || ?
|-
| [[1257 Samalas eruption|Mount Samalas]] || {{INA}} || 1257 || style="text-align:center;" | 38–43<ref>{{cite journal |date=8 August 2015 |last1=Vidal |first1=CélineM. |last2=Komorowski |first2=Jean-Christophe |last3=Métrich |first3=Nicole |last4=Pratomo |first4=Indyo |last5=Kartadinata |first5=Nugraha |last6=Prambada |first6=Oktory |last7=Michel |first7=Agnès |last8=Carazzo |first8=Guillaume |last9=Lavigne |first9=Franck |last10=Rodysill |first10=Jessica |last11=Fontijn |first11=Karen |title=Dynamics of the major plinian eruption of Samalas in 1257 A.D. (Lombok, Indonesia) |journal=Bulletin of Volcanology |volume=77 |issue=9 |pages=73 |doi=10.1007/s00445-015-0960-9 |bibcode=2015BVol...77...73V |s2cid=127929333}}</ref> || style="text-align:center;" | 7<ref>{{cite journal |date=22 January 2015 |last1=Whelley |first1=Patrick L. |last2=Newhall |first2=Christopher G. |last3=Bradley |first3=Kyle E. |title=The frequency of explosive volcanic eruptions in Southeast Asia |journal=Bulletin of Volcanology |volume=77 |issue=1 |pages=1–11 |doi=10.1007/s00445-014-0893-8 |pmid=26097277 |pmc=4470363 |bibcode=2015BVol...77....1W}}</ref> || style="text-align:center;" | −1.2<ref>{{cite journal |date=2017 |last1=Guillet |first1=Sébastien |last2=Corona |first2=Christophe |last3=Stoffel |first3=Markus |last4=Khodri |first4=Myriam |last5=Lavigne |first5=Franck |last6=Ortega |first6=Pablo |last7=Eckert |first7=Nicolas |last8=Sielenou |first8=Pascal Dkengne |last9=Daux |first9=Valérie |last10=(Sidorova) |first10=Olga V. Churakova |last11=Davi |first11=Nicole |last12=Edouard |first12=Jean-Louis |last13=Zhang |first13=Yong |last14=Luckman |first14=Brian H. |last15=Myglan |first15=Vladimir S. |last16=Guiot |first16=Joël |last17=Beniston |first17=Martin |last18=Masson-Delmotte |first18=Valérie |last19=Oppenheimer |first19=Clive |title=Climate response to the Samalas volcanic eruption in 1257 revealed by proxy records |journal=Nature Geoscience |volume=10 |issue=2 |pages=123–128 |doi=10.1038/ngeo2875 |url=http://centaur.reading.ac.uk/68817/1/Guillet_et_al_1257_1258_Nature_Geoscience_Format_Final.pdf |bibcode=2017NatGe..10..123G |s2cid=133586732 |access-date=30 June 2019 |archive-date=28 April 2019 |archive-url=https://web.archive.org/web/20190428122608/http://centaur.reading.ac.uk/68817/1/Guillet_et_al_1257_1258_Nature_Geoscience_Format_Final.pdf |url-status=live }}</ref> || ?
|-
| [[1452/1453 mystery eruption]] || Unknown || 1452 || style="text-align:center;" | ? || style="text-align:center;" | 7 || style="text-align:center;" | −0.5 || ?
|-
| [[Huaynaputina]] || {{PER}} || 1600 || style="text-align:center;" | 46 || style="text-align:center;" | 6 || style="text-align:center;" | −0.8 || ≈1,400
|-
| '''Mount Tambora''' || {{INA}} || '''1815''' || style="text-align:center;" | '''44'''<ref>{{Cite web |url=http://volcano.oregonstate.edu/vwdocs/volc_images/southeast_asia/indonesia/tambora.html |title=Tambora, Sumbawa, Indonesia |website=volcano.oregonstate.edu |access-date=2019-02-26 |archive-date=17 June 2017 |archive-url=https://web.archive.org/web/20170617194416/http://volcano.oregonstate.edu/vwdocs/volc_images/southeast_asia/indonesia/tambora.html |url-status=dead }}</ref> || style="text-align:center;" | '''7''' || style="text-align:center;" | '''−0.5''' || '''>71,000'''
|-
| [[Krakatoa]] || {{INA}} || 1883 || style="text-align:center;" | 80 || style="text-align:center;" | 6 || style="text-align:center;" | −0.3 || 36,600
|-
| [[Santa María (volcano)|Santa María Volcano]] || {{GUA}} || 1902 || style="text-align:center;"| 34 || style="text-align:center;"| 6 || style="text-align:center;" | no anomaly || 7,000–13,000
|-
| [[Novarupta]] || {{USA}} || 1912 || style="text-align:center;"| 32 || style="text-align:center;" | 6 || style="text-align:center;" | −0.4 || 2
|-
| [[1980 eruption of Mount St. Helens|Mount St. Helens]] || {{USA}} || 1980 || style="text-align:center;" | 24 || style="text-align:center;" | 5 || style="text-align:center;" | no anomaly || 57
|-
| [[El Chichón]] || {{MEX}} || 1982 || style="text-align:center;" | 32 || style="text-align:center;"| 5 || style="text-align:center;" | ? || >2,000
|-
| [[Nevado del Ruiz]] || {{COL}} || 1985 || style="text-align:center;" | 27 || style="text-align:center;" | 3 || style="text-align:center;" | no anomaly || 23,000
|-
| [[1991 eruption of Mount Pinatubo|Mount Pinatubo]] || {{PHI}} || 1991 || style="text-align:center;" | 34 || style="text-align:center;" | 6 || style="text-align:center;" | −0.5 || 1,202
|-
|[[2022 Hunga Tonga–Hunga Haʻapai eruption and tsunami|Hunga Tonga–Hunga Haʻapai]] ||{{TON}} || 2022 || style="text-align:center;"| 58 || style="text-align:center;"| 5–6 || style="text-align:center;"| ? ||6
|-
| colspan=7 | <span style="font-size:smaller;">Sources: Oppenheimer (2003),<ref name="Oppenheimer2003"/> and [[Smithsonian Institution]]'s [[Global Volcanism Program]]<ref>{{cite web |title=Large Holocene Eruptions |publisher=[[Smithsonian Institution]] |access-date=7 November 2006 |work=Global Volcanism Program |url=http://www.volcano.si.edu/world/largeeruptions.cfm?sortorder=asc |archive-url=https://web.archive.org/web/20130507134343/http://volcano.si.edu/world/largeeruptions.cfm?sortorder=asc |url-status=dead |archive-date=7 May 2013}}</ref></span>
|-
|}

===== Global effects =====
[[File:Greenland sulfate.png|thumb|right|[[Sulfate]] concentration in [[ice core]] from Central [[Greenland]], dated by counting [[oxygen isotope]] seasonal variations. There is an unknown eruption around the 1810s.<ref name="Dai1991">{{cite journal |last1=Dai |first1=J. |first2=E. |last2=Mosley-Thompson |first3=L.G. |last3=Thompson |date=1991 |title=Ice core evidence for an explosive tropical volcanic eruption six years preceding Tambora |url=https://pdfs.semanticscholar.org/4574/f163f9c8321c258cf88710e69e0fd0a3de13.pdf |archive-url=https://web.archive.org/web/20180802194725/https://pdfs.semanticscholar.org/4574/f163f9c8321c258cf88710e69e0fd0a3de13.pdf |url-status=dead |archive-date=2018-08-02 |journal=Journal of Geophysical Research: Atmospheres |volume=96 |issue=D9 |pages=17361–17366 |doi=10.1029/91JD01634 |access-date=2 August 2018 |bibcode=1991JGR....9617361D |s2cid=8384563}}</ref>]]
{{see also|Year Without a Summer}}

The 1815 eruption released 10 to 120 million tons of [[sulfur]]<ref name="Oppenheimer2003"/> into the [[stratosphere]], causing a global climate anomaly. Different methods have been used to estimate the ejected sulfur mass: the [[petrological]] method, an optical depth measurement based on [[anatomy|anatomical]] observations, and the [[polar region|polar]] [[ice core]] sulfate concentration method, which calibrated against cores from [[Greenland]] and [[Antarctica]].

In the spring and summer of 1816, a persistent stratospheric sulfate [[aerosol]] veil, described then as a "dry fog", was observed in the northeastern United States. It was not dispersed by wind or rainfall, and it reddened and dimmed sunlight to an extent that sunspots were visible to the naked eye.<ref name="Oppenheimer2003"/> Areas of the [[northern hemisphere]] suffered extreme weather conditions and 1816 became known as the "[[Year Without a Summer|year without a summer]]". Average global temperatures decreased about {{convert|0.4|to|0.7|C-change|1}},<ref name="Stothers1984"/> enough to cause significant agricultural problems around the globe. After 4 June 1816, when there were frosts in [[Connecticut]], cold weather expanded over most of [[New England]]. On 6 June 1816, it snowed in [[Albany, New York]] and [[Dennysville, Maine]]. Similar conditions persisted for at least three months, ruining most crops across North America while Canada experienced extreme cold. Snow fell until 10 June near [[Quebec City]], accumulating to {{convert|30|cm|in}}.<ref name="Oppenheimer2003"/>

That year became the second-coldest year in the northern hemisphere since 1400,<ref name="Briffa1998"/> while the 1810s were the coldest decade on record, a result of Tambora's eruption and other suspected volcanic events between 1809 and 1810.<ref>{{cite journal |last1=Cole-Dai |first1=Jihong |last2=Ferris |first2=David |last3=Lanciki |first3=Alyson |last4=Savarino |first4=Joël |last5=Baroni |first5=Mélanie |last6=Thiemens |first6=Mark H. |title=Cold decade (AD 1810–1819) caused by Tambora (1815) and another (1809) stratospheric volcanic eruption |journal=Geophysical Research Letters |date=1 November 2009 |volume=36 |issue=22 |pages=L22703 |doi=10.1029/2009GL040882 |url=https://hal.archives-ouvertes.fr/hal-01757253/file/cole_dai_grl_09.pdf |bibcode=2009GeoRL..3622703C |s2cid=10579910 |access-date=30 June 2019 |archive-date=6 December 2019 |archive-url=https://web.archive.org/web/20191206085906/https://hal.archives-ouvertes.fr/hal-01757253/file/cole_dai_grl_09.pdf |url-status=live }}</ref> (See sulfate concentration chart.) Surface-temperature anomalies during the summers of 1816, 1817 and 1818 were −0.51, −0.44 and −0.29&nbsp;°C, respectively.<ref name="Briffa1998"/> Along with a cooler summer, parts of Europe experienced a stormier winter,<ref name="Oppenheimer2003"/> and the [[Elbe River|Elbe]] and [[Ohře River]]s froze over for twelve days in February 1816. As a result, prices of [[wheat]], [[rye]], [[barley]] and [[oats]] rose dramatically by 1817.<ref name="Brazdil2016">{{cite journal |date=2016 |last1=Brázdil |first1=Rudolf |last2=Řezníčková |first2=Ladislava |last3=Valášek |first3=Hubert |last4=Dolák |first4=Lukáš |last5=Kotyza |first5=Oldřich |title=Climatic effects and impacts of the 1815 eruption of Mount Tambora in the Czech Lands |journal=Climate of the Past |volume=12 |issue=6 |pages=1361–1374 |doi=10.5194/cp-12-1361-2016 |bibcode=2016CliPa..12.1361B |doi-access=free}}</ref>

This climate anomaly has been cited as a reason for the severity of the 1816–19 [[typhus]] epidemic in southeast Europe and the eastern Mediterranean.<ref name="Oppenheimer2003"/> Large numbers of livestock died in [[New England]] during the winter of 1816–1817, while cool temperatures and heavy rains led to failed harvests in the British Isles. Families in [[Wales]] travelled long distances as refugees, begging for food. Famine was prevalent in north and southwest Ireland, following the failure of wheat, oat and potato harvests. The crisis was severe in Germany, where food prices rose sharply. Demonstrations at grain markets and bakeries, followed by riots, arson and looting, took place in many European cities. It was the worst famine of the 19th century.<ref name="Oppenheimer2003"/>