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Anak Krakatoa: The dark history of volcano emerging from the sea | Indonesia News

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It was just after 9pm on Saturday when Anak Krakatoa, a volcano located in the Sunda Strait between the Indonesian islands of Java and Sumatra, erupted.

Twenty-four minutes later, a devastating tsunami struck the nearby rim of the strait, killing hundreds of unsuspected people and causing widespread destruction.

It was just the latest eruption of Anak Krakatoa, which has been active sporadically since emerging from the sea in the 1920s – more recently, it has been spewing ash and lava since June.

Experts say the tsunami, or seismic sea wave, was likely caused by the collapse of a big portion of Anak Krakatoa’s southern flank. They believe this triggered underwater landslides which displaced water to create the large killer waves.

“Underwater landside is the leading theory,” Sam Taylor-Offord, a seismologist at GNS Science in Wellington, said on Monday.

“So when that land pushes into the ocean … it displaces the ocean surface causing the vertical displacement that causes the tsunami,” he added, noting however that the lack of data and access made it impossible to ascertain this theory.

Ben van der Pluijm, an earthquake geologist and professor at the University of Michigan, also said the tsunami may have been caused by Anak Krakatoa’s partial collapse.

“Instability of the slope of an active volcano can create a rock slide that moves a large volume of water, creating local tsunami waves that can be very powerful. This is like suddenly dropping a bag of sand in a tub filled with water,” he said.





 

‘1883 explosion heard around the world’

Anak Krakatoa formed over years after the explosive eruption of the Krakatoa volcano in 1883, one of the largest and most catastrophic in recorded history.

Before 1883, the only confirmed eruption on the Krakatoa island group was a moderate one some two centuries before, in 1680.

But at 1pm on August 26, 1883, the first in a series of increasingly violent explosions sent a black cloud of ash 27km above Krakatoa.

The climax was reached at 10am the following day, with tremendous blasts that were heard some 3,500km away in Australia, ash that reached a height of 80km and a series of powerful, far-reaching tsunamis – the event was described as “the explosion heard around the world”.

Some 36,000 people were killed in Java and Sumatra in the tsunamis that followed the volcano’s collapse, with the greatest wave reaching a height of 37 metres.

‘Child of Krakatoa’

Krakatoa’s discharge sent nearly 21 cubic km of rock fragments into the air, while big large quantities of ash fell over an area of some 800,000 square km – as a result, the region surrounding the volcano was plunged into darkness for more than two days.

The dust drifted several times around the globe, creating dramatic red and orange sunsets throughout the following year. A global temperature drop was also recorded. 

A thick layer of sterile ash meanwhile covered everything on Krakatoa, and plant and animal life did not begin to reestablish itself for five years.

Krakatoa remained quiet until December 1927, when a new eruption started on the seafloor along the same line as the previous cones. In early 1928, a rising cone reached sea level, and by 1930 it had become a small island – Anak Krakatoa, or “child of Krakatoa”.

Anak Krakatoa’s cone has continuing to grow ever since, and it’s currently standing at an elevation of about 300 metres above the sea.

With the exact cause of the disaster still unknown, and Anak Krakotoa still rumbling, authorities and scientists are wary of the risk of a tsunami recurrence.

“The likelihood of further tsunamis in the Sunda Strait will remain high while Anak Krakatoa volcano is going through its current active phase because that might trigger further submarine landslides,” Richard Teeuw, of the University of Portsmouth in England, said.

Teeuw said that sonar surveys would now be needed to map the seafloor around the volcano, but “unfortunately submarine surveys typically take many months to organise and carry out,” he added.

But “devastating tsunami caused by volcanic eruptions are rare; one of the most famous (and deadly) was caused by the eruption of Krakatoa in 1883”.

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Ottawa transit commission hopes to prioritize COVID-19 vaccines for OC Transpo workers

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Ottawa’s transit commission is pushing local and provincial health officials to recognize the role OC Transpo operators have played in keeping the city running during the COVID-19 pandemic, hoping to bump train and bus drivers in the vaccination queue amid a recent surge in coronavirus infections affecting transit workers.

More than 100 OC Transpo staff across the entire organization have tested positive for the coronavirus since the start of the pandemic, according to an update at Wednesday morning’s transit commission meeting.

Of those cases, 26 employees are currently recovering from the disease in self-isolation.

OC Transpo has seen a recent jump in COVID-19 cases, with Ottawa city council receiving reports of eight operators testing positive for the virus over a recent eight-day period.

Transit commissioner Sarah Wright-Gilbert attempted to find out how many of the total cases are traced to workplace transmission, but OC Transpo boss John Manconi said he’s been advised by medical officer of health Dr. Vera Etches that he can’t share that information for privacy reasons.

Transit operators are listed in the second priority group of essential workers as part of Ontario’s COVID-19 vaccine sequencing plans, but several commissioners speaking Wednesday wanted to get the city’s bus and train drivers bumped higher in the order.

Councillors Riley Brockington and Glen Gower both put forward motions looking to get front-line OC Transpo employees prioritization in vaccine sequencing, but others pointed out that the much-debated public health topic of who gets the vaccine and when is well beyond the scope of the transit commission.

“We are not in a position in transit commission to be decreeing, or making an edict, about what group of essential workers is more at risk than others and should be prioritized. That should be left up to public health experts,” Wright-Gilbert said.

Knoxdale-Merivale Coun. Keith Egli, who also chairs the Ottawa Board of Health, reflected on the board’s four-plus-hour meeting on Monday evening, during which vaccine sequencing and prioritizing essential workers dominated the conversation.

“Vaccine sequencing is obviously a very difficult maze to get through,” he said.

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COVID-19: Ottawa police announce end of 24-7 presence at Ontario-Quebec border

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Less than two days after the Ontario government’s latest COVID-19 restrictions came into effect, calling for non-essential traffic to be stopped at the province’s borders with Quebec and Manitoba, the Ottawa Police Service has announced it is stopping its 24-hour checkpoints.

According to a statement issued by the service Tuesday evening, the around-the-clock border checkpoints were set to end as of 8 p.m. on Tuesday in favour of rotating checkpoints across the city throughout the day until Ontario’s temporary regulations end.

“Since the onset of the border operations, the OPS has been working closely with Ottawa Public Health (OPH) along with local stakeholders and interprovincial stakeholders (the City of Ottawa, the City of Gatineau, the Ontario Provincial Police etc.) to assess any local public health, traffic and safety impacts. The assessment resulted in today’s operational changes,” the statement said.

“The operational changes announced today are designed to better ensure the health and safety of all, to minimize delays and/or hazards for travellers and to ensure essential workers can get to their places of employment on time.”

The statement also said the police service, while working to comply with the provincial order, was focused on education and enforcement actions that “support improved public health outcomes and respect the concerns of our most marginalized and racialized communities”

Officers said they will be conducting daily assessments on border crossings and that there could be further changes.

In a statement to Global News, a spokesperson for Solicitor General Sylvia Jones said that the border closures are ultimately subject to the discretion of local police enforcing the regulations.

“Local police services are best positioned to determine the operational deployments necessary to ensure the continued safety of their communities,” the spokesperson said, noting that the order’s regulations still apply to individuals entering the province.

The temporary order restricts Quebec residents from entering Ontario. If prompted, individuals must stop when directed by an enforcement officials and provide their reason for entering the province.

The main exemptions to the restrictions include if the person’s main home is in the province, if they work in Ontario, if they’re transporting goods, if they’re exercising Indigenous or treaty rights, if they need health care or if there’s a basis on compassionate grounds.

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COVID-19 vaccines in Ottawa: Nearly half of all residents in their 60s have at least one dose

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OTTAWA — Ottawa Public Health’s latest COVID-19 vaccination update shows that nearly half of all residents 60 to 69 years old have had at least one dose of a COVID-19 vaccine, a figure that has all but doubled in the past week.

OPH’s COVID-19 vaccination dashboard shows 58,000 residents 60 to 69 have had at least one dose of a COVID-19 vaccine, accounting for 49.3 per cent of that age group’s population in Ottawa. Last Wednesday, OPH reported 30,000 residents 60 to 69 had had at least one dose, which was 25.4 per cent.

As age demographics get younger, the population grows larger and the coverage by percentage may appear to grow more slowly, even if clinics are vaccinating greater numbers of people. For example, the latest figures show that 83 per cent of people aged 70 to 79 have had at least one dose. By raw population that’s 60,000 people, only slightly higher than half of all people in their 60s.

Vaccinations are open through the Ontario portal to anyone 60 and older and, this week, the AstraZeneca vaccine was approved for administration at pharmacies and primary care clinics to anyone in Ontario 40 and older.

OPH reported a new shipment this week of 25,740 doses of the Pfizer-BioNTech vaccine. To date, Ottawa has received 305,130 doses of COVID-19 vaccines from the provincial government.

The number of eligible residents (i.e. 16 and older) with at least one dose of a vaccine is now up to 28 per cent.

Tuesday was Ottawa’s second-busiest day for vaccinations overall, with the OPH reporting 9,729 shots administered. Last Friday saw 9,887 shots administered in a single day.

QUICK STATS

  • Ottawa residents with at least one dose: 248,668
  • Ottawa residents with two doses: 26,722
  • Percent of eligible population (residents 16 and older) with at least one dose: 28 per cent
  • Percent of eligible population (residents 16 and older) with two doses: 3 per cent
  • Percent of total population with at least one dose: 24 per cent
  • Percent of total population with two doses: 3 per cent

VACCINATION COVERAGE BY AGE FOR OTTAWA RESIDENTS WITH AT LEAST ONE DOSE

  • 10-19: 1.6 per cent (1,804 people)
  • 20-29: 8.3 per cent (13,452 people)
  • 30-39: 9.5 per cent (14,999 people)
  • 40-49: 12.9 per cent (17,350 people)
  • 50-59: 28.8 per cent (40,320 people)
  • 60-69: 49.3 per cent (58,627 people)
  • 70-79: 82.9 per cent (62,808 people)
  • 80-89: 87.5 per cent (29,358 people)
  • 90+: 89.2 per cent (7,893 people)
  • Unknown age: 2,057 people 

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