What was the largest seismic event in recorded history?
28756686#6
The largest event prompted concern from local residents. The six borehole seismometers installed near the Basel injection well to monitor the natural background seismicity and the geothermal stimulation recorded more than 13,500 potential events connected with the geothermal project, from which 3,124 were of sufficient quality to permit [hypocenter] determinations in the period 2–12 December 2006, which spanned the main stimulation and the decline in the event rate. During the post-stimulation period from 13 December 2006 onward, a further 350 locatable events were detected up to 2 May 2007, by which time events were occurring sporadically at around one per day. In all, locations for more than 3,500 events were determined.
Induced seismicity in Basel
14579#19
A massive supervolcano erupted at present-day Lake Toba around 70,000 BCE. It is believed to have caused a global volcanic winter and cooling of the climate, and subsequently led to a genetic bottleneck in human evolution, though this is still debated. The 1815 eruption of Mount Tambora and the 1883 eruption of Krakatoa were among the largest in recorded history. The former resulted in 92,000 deaths and created an umbrella of volcanic ash which spread and blanketed parts of the archipelago, and made much of Northern Hemisphere without summer in 1816. The latter produced the loudest sound in recorded history, and resulted in 36,000 deaths that are attributed to the eruption itself and the tsunamis it created. Significant additional effects were also felt around the world years after the eruption. Recent major disasters due to seismic activity include the 2004 Indian Ocean earthquake and the 2006 Yogyakarta earthquake.
Indonesia
372417#0
The 1960 Valdivia earthquake () or Great Chilean earthquake ("Gran terremoto de Chile") of 22 May is the most powerful earthquake ever recorded. Various studies have placed it at 9.4–9.6 on the moment magnitude scale. It occurred in the afternoon (19:11 GMT, 15:11 local time), and lasted approximately 10 minutes. The resulting tsunami affected southern Chile, Hawaii, Japan, the Philippines, eastern New Zealand, southeast Australia and the Aleutian Islands.
1960 Valdivia earthquake
1781824#5
Significant earthquakes centred on Dalton/Gunning include an ML5.3 event on 5 July 1888 that was felt in Sydney and represents the first record of seismic activity in the area; the largest recorded event - an ML5.6 event on 18 November 1934 that was also felt in Sydney and agitated the water in the Manuka Pool in Canberra; an ML5.5 event on 10–11 March 1949 that caused minor cracking in Canberra buildings; and the ML4.3 Oolong event on 9 August 1984 which damaged Oolong Homestead and the Anglican Church.
Dalton, New South Wales
761512#9
The largest NMSZ earthquake of the 20th century was a 5.4-magnitude quake (although it was reported as a 5.5 at the time) on November 9, 1968, near Dale, Illinois. The quake damaged the civic building at Henderson, Kentucky and was felt in 23 states. People in Boston said their buildings swayed. At the time of the quake, it was the biggest recorded quake with an epicenter in Illinois in that state's recorded history. In 2008 in the nearby Wabash Valley Seismic Zone, a similar magnitude 5.4 earthquake occurred with its epicenter in Illinois near West Salem and Mount Carmel.
New Madrid Seismic Zone
28756686#2
In all, between December 2006 and March 2007, the six borehole seismometers installed near the Basel injection well recorded more than 13,500 potential events connected with the geothermal project. The 200 largest were between magnitudes 0.7 and 3.4. Nine of these events had an of 2.5 or larger. The remainder were too small to be observed or felt at the surface. Between December 2 and January 24, 168 seismic events with magnitude greater than 0.6 occurred within 1 km of the wellbore, at depths of 4–5 km, near the well bottom.
Induced seismicity in Basel
10182675#1
The May 31, 1897 event was the strongest in Virginia's history. With a maximum Mercalli intensity of VIII ("Severe") this shock destroyed many chimneys and created ground effects over a large area. It had a magnitude of 5.6 (a seismic scale that is based on an isoseismal map or the event's felt area) and had severe effects in Narrows, where ground motion was observed and the flow of streams was disrupted.
Virginia Seismic Zone
1016556#18
Large-scale fossil fuel extraction can generate earthquakes. Induced seismicity can be also related to underground gas storage operations. The 2013 September–October seismic sequence occurred 21 km off the coast of the Valencia Gulf (Spain) is probably the most known case of induced seismicity related to Underground Gas Storage operations (the Castor Project). In September 2013, after the injection operations started, the Spanish seismic network recorded a sudden increase of seismicity. More than 1,000 events with magnitudes () between 0.7 and 4.3 (the largest earthquake ever associated with gas storage operations) and located close the injection platform were recorded in about 40 days. Due to the significant population concern the Spanish Government halted the operations. By the end of 2014, the Spanish government definitively terminated the concession of the UGS plant. Since January 2015 about 20 people who took part in the transaction and approval of the Castor Project were indicted.
Induced seismicity
4823678#13
The largest flash flood in Twin Cities history occurred on July 23–July 24, 1987. Dubbed locally "The Super Storm", more rain fell from this event than any other in recorded Twin Cities history. The storm caused damage to 9,000 homes, killed two people, and caused $27 million in damage. Some areas in the southern metro area recorded of rain. The that fell on July 23 is the largest official single-day rainfall for the Twin Cities. Overall, at least of rain fell over , and at least fell over . This event was voted the eighth most significant weather event in the state of Minnesota during the 20th century. Three days before this event on July 20–July 21, up to of rain fell over some of these same areas. These two storms combined to help the Twin Cities to their wettest summer on record, with of rain falling from June to August.
Climate of Minneapolis–Saint Paul
761512#5
The zone had four of the largest North American earthquakes in recorded history, with moment magnitudes estimated to be as large as 7.0 or greater, all occurring within a three-month period between December 1811 and February 1812. Many of the published accounts describe the cumulative effects of all the earthquakes (known as the New Madrid Sequence); thus finding the individual effects of each quake can be difficult. Magnitude estimates and epicenters are based on interpretations of historical accounts and may vary.
New Madrid Seismic Zone
6306495#2
On 21 October 2014 SGC raised the alert level for the volcanic complex to orange (level 3 of 4) noting that a seismic swarm characterized by 4,300 earthquakes was detected in an 18-hour period. Hypocenters were located 1–4 km southwest of Chiles volcano at depths of 3–5 km and local magnitudes between M 0.2 and 4.5. Inhabitants felt 11 of the events. On 22 October a report noted that the total number of earthquakes recorded on 21 October 2014 reached 7,717, which was the largest number of earthquakes recorded on one day since the installation of a local seismic network in November 2013. Several swarms have occurred in the area since February 2013. By the end of November 2014 over 132,000 earthquakes occurred within a narrow area .5 – 6 km SW of the summit of Chiles.
Chiles (volcano)