On December 29, 2013, San Miguel volcano, also known as "Chaparrastique", erupted at 10:30 local time, spewing a large column of ash and smoke into the sky; ...
Effects of volcanoes ~ https://upload.wikimedia.org/wikipedia/commons/thumb/c/c5/Vulkan_Chaparrastique,_El_Salvador_2013_01.JPG/220px-Vulkan_Chaparrastique,_El_Salvador_2013_01.JPG
There are many different types of volcanic eruptions and associated activity: phreatic eruptions(steam-generated eruptions), explosive eruption of high-silica lava (e.g., rhyolite), effusive eruption of low-silica lava (e.g., basalt), pyroclastic flows, lahars (debris flow) and carbon dioxide emission. All of these activities can pose a hazard to humans. Earthquakes, hot springs, fumaroles, mud pots and geysers often accompany volcanic activity.
Volcanic gases
The concentrations of different volcanic gases can vary considerably from one volcano to the next.Water vapor is typically the most abundant volcanic gas, followed by carbon dioxide[17] and sulfur dioxide. Other principal volcanic gases include hydrogen sulfide, hydrogen chloride, and hydrogen fluoride. A large number of minor and trace gases are also found in volcanic emissions, for example hydrogen, carbon monoxide, halocarbons, organic compounds, and volatile metal chlorides.
Large, explosive volcanic eruptions inject water vapor (H2O), carbon dioxide (CO2), sulfur dioxide (SO2), hydrogen chloride (HCl), hydrogen fluoride (HF) and ash (pulverized rock and pumice) into the stratosphere to heights of 16–32 kilometres (10–20 mi) above the Earth's surface. The most significant impacts from these injections come from the conversion of sulfur dioxide to sulfuric acid (H2SO4), which condenses rapidly in the stratosphere to form fine sulfate aerosols. It is worth mentioning that the SO2 emissions alone of two different eruptions are sufficient to compare their potential climatic impact.[18] The aerosols increase the Earth's albedo—its reflection of radiation from the Sun back into space – and thus cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere. Several eruptions during the past century have caused a decline in the average temperature at the Earth's surface of up to half a degree (Fahrenheit scale) for periods of one to three years – sulfur dioxide from the eruption of Huaynaputina probably caused the Russian famine of 1601–1603.[19]
Significant consequences
One proposed volcanic winter happened c. 70,000 years ago following the supereruption of Lake Toba on Sumatra island in Indonesia.[20]According to the Toba catastrophe theory to which some anthropologists and archeologists subscribe, it had global consequences,[21]killing most humans then alive and creating a population bottleneck that affected the genetic inheritance of all humans today.[22] The 1815 eruption of Mount Tambora created global climate anomalies that became known as the "Year Without a Summer" because of the effect on North American and European weather.[23] Agricultural crops failed and livestock died in much of the Northern Hemisphere, resulting in one of the worst famines of the 19th century.[24] The freezing winter of 1740–41, which led to widespread famine in northern Europe, may also owe its origins to a volcanic eruption.[25]
It has been suggested that volcanic activity caused or contributed to the End-Ordovician, Permian-Triassic, Late Devonian mass extinctions, and possibly others. The massive eruptive event which formed the Siberian Traps, one of the largest known volcanic events of the last 500 million years of Earth's geological history, continued for a million years and is considered to be the likely cause of the "Great Dying" about 250 million years ago,[26] which is estimated to have killed 90% of species existing at the time.[27]
Lava flow from the Kilauea Volcano burns a Pahoa, Hawaii, home Monday.
Slow-moving lava from Kilauea volcano burns down first Hawaii house
The molten rock hit the Pahoa house in the Big Island just before noon Monday, authorities said. It was the first house burned down by a lava flow from Kilauea volcano that scientists have been warning the public about since August. And it likely won't be the last.
THE ASSOCIATED PRESS ~ http://www.nydailynews.com/news/national/slow-moving-kilauea-volcano-lava-hits-hawaii-house-article-1.2005970
Updated: Tuesday, November 11, 2014, 7:51 AM
HONOLULU — After months of slowly making its way toward communities in a rural part of Hawaii's Big Island, it took an oozing stream of lava just 45 minutes to burn down an empty house.
Firefighters standing by to tackle any spreading wildfires let the flames consume the 1,100-square-foot structure Monday afternoon as a relative of the homeowner watched and recorded video of the destruction with an iPhone.
It was the first house burned down by a lava flow from Kilauea volcano that scientists have been warning the public about since August. And it likely won't be the last.
The home's nearest neighbor is about a half-mile away, Hawaii County Civil Defense Director Darryl Oliveira said. A garage and barn structure near the destroyed home could also burn down soon, he said.
The lava emerged from a vent in June and entered Pahoa Oct. 26, when it crossed a country road at the edge of town. Since then, it has smothered part of a cemetery and burned down a garden shed. It also burned tires, some metal materials and mostly vegetation in its path.
The leading edge of the lava flow had bypassed the home, but it was a lobe of lava that broke out upslope and widened that reached the house. Where the lava will reach next, and when, is hard to predict.
The county estimates the value of the destroyed home at about $200,000, Oliveira said. The renters of the home left in August, he said.
Oliveira said officials would make arrangements for homeowners to watch any homes burn as a means of closure and to document the destruction for insurance purposes.
The leading edge of the molten rock had stalled Oct. 30, but lava was breaking away at several spots upslope. The leading edge remained about 480 feet from Pahoa Village Road on Monday, a main street that goes through downtown.
STAFF SGT. KATIE GRAY / HANDOUT/EPALava flow closest to the town of Pahoa burned its first house after stalling approximately 480 feet away from Pahoa Village Road earlier this week.
Crews have been working on alternate routes to be used when lava hits Highway 130, considered a lifeline for the Puna district.
Many residents have evacuated or are ready to leave if necessary.
Imelda Raras lives on the other end of Apaa Street from where the lava burned its first house. She and her family have put a lot of their belongings in storage and are prepared to go to a friend's home if the lava gets close.
"I'm scared right now," she said as she watched smoke from the burning house. "What will happen next? We will be waiting."
The homeowner of the house that burned had arranged weeks ago to relocate horses and other animals, Raras said.
Raras said she's thinking about the mounting storage costs.
"I think our lives will be unstable," she said. "I hope our house will be spared."
The family is ready to go, but Raras said they will do so with heavy hearts. "Because it's hard to leave your own house," she said. "It's one of the hardest things to do."