Pompeii's Pyroclastic Flow

We are continuing on our tour of Ancient Pompeii. This is documentary is called the Riddle of Pompeii, it explores the mystery of Pompeii and it explores the pyroclastic flow.  This is another documentary that you can put in your files for a class movie day.  It would be a good documentary to show in an earth science class as well.  There is an in-depth exploration of a volcanic eruption and what happened when Vesuvius exploded.

Lava has regularly flowed from Vesuvius and its most recent eruption happened in 1944.  This eruption was recorded on video.  In 1944 only twenty people died.  Lava flows do not kill people because they flow slow.  So why was the death toll in Pompeii was so high?  What made Vesuvius eruption unique in history?

In 1748, excavation in Pompeii began.  Digging was easy.  Pompeii was buried by pumice instead of lava.  Archeologists discovered that skeletons were found in hollows.  They decided to pour plaster into those hollows revealing the body.  With modern-day scanning, anthropologists are seeing what happened to the people. 

Pliny the Younger reported what happened to Pompeii during the eruption of Vesuvius.  His uncle, Pliny the Elder went out to try to help the people evacuate.  Vesuvius started its eruption at noon and recorded what the volcanic cloud looked like.  Based on scientific observations of the pumice that filled the area, the scientists discovered that Pliny’s description was right.  In the centuries previous to the major eruption, lava was able to escape.  However the volcano got plugged up, and pressure built underneath that plug.  Finally, that plug broke and the volcano exploded to deadly consequences for the city of Pompeii.

One theory is that the people in Pompeii survived the initial pumice fall.  People were able to cover their heads to protect them from the pumice.  However, people were unaware of the deadly punch Vesuvius was going to pack.  Pliny the Elder had figured that Vesuvius was a dormant volcano and had written about Mount Etna, so volcanos were not unfamiliar to the people of Pompeii.  Pompeiians were familiar with earthquakes, so they decided to stay put.

Mapping the site demonstrates the reluctance of people to leave their city.  They may have gone to check on families or friends but they did not want to leave.  A few of the bodies were found with iron house keys.  Unfortunately, the rate of pumice falling increased.  By the late afternoon, the roofs of the house started to collapse.  People started to leave Pompeii.  Sadly, not everyone was able to leave.

Everyone had their reasons for staying in Pompeii.  A family would leave due to a pregnancy in the family.  Another could leave because of a sick family member.  A person was in too much pain to leave.  DNA is revealing some of the reasons why people would not flee Pompeii.

Pliny the Elder eventually would send out the Navy to help people flee from Pompeii.  However, they were driven back.  Finally, they were forced to take shelter down the coast.  Pliny the Elder would eventually die as a result of Vesuvius.  In the meantime, pumice continued to get deeper and deeper.  People continued to walk on top of the pumice to escape.  Their bodies were found near the surface and these people died by suffocation.  Some bodies were found with their mouths open, while others were stretched out as if seeking clean air.

To find out more continue to watch the documentary.  In the meantime, keep this documentary in your files to share with a class.

You can access the YouTube video here.