Archive | December 21, 2017

MAGNITUDE 3.4 SPAIN

https://www.emsc-csem.org/Earthquake/earthquake.php?id=636977

Subject to change

Depth: 20 km

Distances: 371 km E of Gibraltar, Gibraltar / pop: 26,600 / local time: 20:21:42.2 2017-12-21
96 km S of Murcia, Spain / pop: 437,000 / local time: 20:21:42.2 2017-12-21
43 km SE of Pulpí, Spain / pop: 7,500 / local time: 20:21:42.2 2017-12-21

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MAGNITUDE 5.2 CENTRAL IRAN

https://www.emsc-csem.org/Earthquake/earthquake.php?id=636969

Subject to change

Depth: 20 km

Distances: 413 km NE of Shīrāz, Iran, Islamic Republic of / pop: 1,250,000 / local time: 20:34:47.6 2017-12-21
140 km NW of Kermān, Iran, Islamic Republic of / pop: 578,000 / local time: 20:34:47.6 2017-12-21
47 km W of Rāvar, Iran, Islamic Republic of / pop: 40,200 / local time: 20:34:47.6 2017-12-21

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YELLOWSTONE MAGNITUDE 2.9 SOUTHERN IDAHO, USA

Subject to change
Depth: 12 km

Distances: 756 km S of Calgary, Canada / pop: 1,020,000 / local time: 04:31:32.7 2017-12-21
150 km NE of Boise, United States / pop: 146,000 / local time: 04:31:32.7 2017-12-21
38 km SW of Challis, United States / pop: 1,100 / local time: 04:31:32.7 2017-12-21

 

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Solar activity has fallen to the bottom of the next minimum of the 11-year solar cycle 1.5 years earlier than the schedule

sunny wind
The influence of the solar wind on the Earth (schematic image). The source is noaa.gov
Weak perturbations of the Earth’s magnetic field, sometimes reaching the level of a magnetic storm, are observed on our planet during the last days – approximately from the middle of Sunday. Most of this time, the magnetosphere is in a perturbed state, to which the value of the index Kp = 4 corresponds. Twice during this time, the amplitude of the field oscillations rose for a short time to Kp = 5, which corresponds to a weak storm, but the duration of these intervals was only 1-2 hours. In general, the occurring geomagnetic event is extremely weak.
 
None of the magnetic storms and none of the field disturbances observed in the last two months were related to solar activity. Thus, the cosmic weather in the vicinity of our planet is increasingly losing its connection with the Sun, which by all indications practically fell to the bottom of the next minimum of the 11-year solar cycle 1.5 years earlier than the schedule. Against this background, with the complete absence of even the weakest flares on the Sun, the main factor of cosmic weather was the solar wind – a plasma stream formed as a result of the continuous outflow of the upper layers of the solar atmosphere into the surrounding outer space. When the density or velocity of this stream changes, so does the pressure that it exerts on the earth’s magnetosphere – it is then amplified or weakened. The Earth’s field at the same time is out of balance and experiences fluctuations, which is observed as a storm. In this sense, the graph of magnetic storms now almost exactly reflects the graph of the change in the speed of the solar wind. This allows, even without looking at the data of spacecraft, from the very fact of the onset of magnetic disturbances, to conclude that the Earth has entered a faster stream of solar wind.
 
If you still look at the satellite data, then the speed of the solar wind blowing the Earth is now about 650 km / s and compared to the middle of yesterday increased by more than 50% – from 400 km / sec. Significantly increased now is the temperature of the wind – from 100 thousand degrees it has grown to almost half a million degrees. Strong oscillations of the interplanetary magnetic field are also observed, which further enhances the effect of wind on the magnetosphere of the Earth.
 
The observed disturbances should not last more than several hours, although certain fluctuations of the Earth’s field can be observed for about a day.
 
In general, we must understand that the effect of the solar wind on the Earth is very weak, and, in principle, can not cause strong magnetic storms. The main reason for really large disturbances affecting communications, spacecraft traffic and terrestrial electrical networks is only solar activity. Nevertheless, the Sun seems to finally release (or even already released) the Earth from its hands, so the main factor of space weather for the coming years will be the solar wind – at least until our star wakes up from sleep. A certain advantage of this situation, in addition to reducing the strength of magnetic storms, will be their better predictability. Unlike solar flares, the exact prediction of which has very low reliability, the solar wind speed is predicted much better and at much longer terms.
Courtesy of tesis.lebedev.ru

Buildings damaged, thousands remain without power after severe storms hit Victoria, Australia

Severe Thunderstorm Warning Alert
The State Emergency Service (SES) said they had received hundreds of calls for assistance after storms brewed on yesterday afternoon.
 
A severe thunderstorm warning for damaging winds, heavy rain and large hailstones remains current for much of the state.
 
More than 30,000 homes properties are still without power, down from about 100,000 around the state last night.
 
Power was also out in parts of suburban Melbourne but the impact was far less significant.
 
The weather bureau’s Dean Stewart said Melbourne received 20 millimetres of rain within 15 minutes, causing flash flooding in many suburbs.
 
“The highest wind gust in the state was up at Kilmore Gap to the north of Melbourne — 117 kilometre per hour — but a lot of towns reported gusts over 100kph, [followed by] Wangaratta with 113kph, Bendigo 111kph, Mangalore 107kph, Laverton 98kph,” he said.
A house missing roof at Merbein, in Victoria's north-west, after a severe storm passed through.
PHOTO: The roof was torn off one house at Merbein. (Supplied: Leonie Dam)
A fierce storm battered Mildura and parts of Victoria’s north-west as a cool change brought strong winds and a dramatic temperature drop to Melbourne.
 
More than 100 calls for assistance were made to the State Emergency Service (SES) in Mildura alone, stretching the town’s resources and leading for a request for back-up from CFA volunteers.
 
Wind gusts of 89 kilometres per hour were also recorded in Mildura and a number of buildings were damaged in the area, including at Merbein and Irymple.
 
One house in Merbein lost its roof, while grape vines were blown over at Curlwaa.
 
Large hail fell in eastern suburbs, including Mitcham and Narre Warren. A number of suburbs also experienced flash flooding.
 
Trams in the city were interrupted by flash flooding and lanes were closed on CityLink, while some metropolitan and regional train services were also delayed.
A woman holds large hail stones in her hand.
PHOTO: A number of suburbs across Melbourne experienced large hail. (Twitter: Jenna Blyth)
Shops at Highpoint, one of Melbourne’s busiest shopping centres, were flooded.
 
Swan Hill reached 41 degrees Celsius, while Mildura hit 39 degrees as the north-west of the state sweltered through hot and humid conditions.
 
Melbourne sweltered through a hot night, falling to just 24 degrees at 12:38am, and reached a maximum of 37 degrees just before 3:30pm.
 
But when the cool change hit the CBD about an hour later, the temperature fell 12 degrees in 10 minutes.
 
Very dangerous winds could hit Western Port, the Mornington Peninsula and parts of Port Phillip, with possible winds of over 125 kilometres per hour.
 
Residents in Werribee, in Melbourne’s west, said the suburb had experienced very strong wind gusts, while buildings have been damaged in Tarneit.
 
There are reports of a number of trees down across the state.
A number of shops are flooded at Highpoint Shopping Centre, in Melbourne's west.
PHOTO: A number of shops were flooded at Highpoint shopping centre. (ABC News: Jessica Longbottom)
Courtesy of abc.net.au

MAGNITUDE 5.7 IZU ISLANDS, JAPAN REGION

https://www.emsc-csem.org/Earthquake/earthquake.php?id=636881

Subject to change

Depth: 10 km

Distances: 764 km S of Tokyo, Japan / pop: 8,337,000 / local time: 12:00:17.7 2017-12-21
1589 km N of Saipan, Northern Mariana Islands / pop: 48,300 / local time: 13:00:17.7 2017-12-21
1722 km SE of Seoul, Korea, Republic of / pop: 10,350,000 / local time: 12:00:17.7 2017-12-21

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