ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel
  • »
  • Education and Science»
  • Geology & Atmospheric Science

Pororoca - The Most Dangerous Wave

Updated on December 30, 2011

Twice a year an amazing effect takes place between the months of February and March in the Amazonas river, Brasil, known as the Pororoca.

The action of the powerful Atlantic Ocean tide surges into the river for several kilometers, making it one of the longest tidal bores in the world.

The wave can be heard about 30 minutes before its arrival (like the rumble of an oncoming train), and it's so powerful that it can destroy anything.

For hundreds of years the natives have called it "pororó-ká" which in the local Tupi-Guarani language means “great destructive roar”.

The Pororoca
The Pororoca
The Amazon River
The Amazon River
Mouths Of The Amazon
Mouths Of The Amazon

Dynamics Of The Pororoca

The Earth's tides are caused by the gravitational attraction of both the sun and moon on the Earth's waters. High spring tides occur whenever the Earth, moon, and sun line up and reinforce each other. These tides fall after both the new and full moon.

Tidal bores are natural phenomena provoked by the pressure of the ocean’s rising tide intersecting with the mouth of a river. When a watercourse is forced to cope with a rapid rise in sea level, it can lead to a big confrontation. This phenomenon culminates in a complete reversal of the direction of the flow. As this flow is reversed, it forms a powerful and penetrating wave that plows upstream.

In the open ocean a tide wave is symmetrical. As it encounters shallow water near shore, the crest travels at a greater speed than the base, causing the wave to steepen. Once the crest overtakes the trough, the peak sharpens. A discernible head wave is formed and a bore is born.

The Pororoca is caused by the tides of the Atlantic Ocean wich meet the mouth of the Amazonas river. This originates when the growing tide of Atlantic meets with the descending current of the Amazonas.

The collision of these two enormous masses of water produces a wave, whose energy reverse the direction of the flow. The dynamics is similar to the crash between two tectonic plates that produce an earthquak.

Characteristic Of The Pororoca

The great noise is caused by the strong opposition between the marine flow and the fluvial flow in inverse direction. The flow rate of the Amazona river is 100.000 cubic meters per second.

The brown color of the water is due to the flow drags stones, mud and sediments of the bottom of the river.

The tidal bore starts with a roar, constantly increasing, and advances at the rate of from 15–25 km/h, with a breaking wall of water from 1.5–4.0 metres high. Travel as much as 13 kilometers inland upstream.

Consequences Of The Pororoca

The wave is very powerful and can destroy anything. It makes a thunderous sound that causes animals to flee, and creates an uncontrolled jumble of coastal birds that instinctively escape from their perches near the bed of the huge river.

The power of this natural phenomenon can be seen in the way it significantly eats away at the river’s edges, devastating trees, local houses, islands, rocks, and virtually anything in its path.

It also has positive effects, since due to the mixture of the river with the ocean, the fishing in the riversides is abundant, with sea and river species.

Surfing The Pororoca

The wave has become popular with surfers. However, surfing the Pororoca is especially dangerous, as the water contains a significant amount of debris (often, entire trees), and sweeps up wild animals, like snakes (the anaconda) alligators, spiders, piranha, and even jaguar.

Add to those risks the Candiru, a small parasitic fish that can swim up a person's urethra, dig in its spines, and feast on its host's blood. The invader can only be removed by surgery.

Still, the bores remain an irresistible temptation for dozens of surfers. Since 1999, an annual championship has been held in São Domingos do Capim.

While the waves are often smaller than those known to ocean surfers, they can ride waves far longer than their ocean counterparts, who are lucky to get a full minute of wave-riding time.

Surfers have managed to ride these Amazonian waves for more than 15 minutes.

The current record is held by Brazilian Picuruta Salazar, who in 2003 managed to ride the wave for 37 minutes and travel 12.5 kilometers.

Comments

    0 of 8192 characters used
    Post Comment

    • StefanMDP profile image
      Author

      StefanMDP 6 years ago

      Hi Paul.

      Thanks for stopping by.

    • eregouf profile image

      eregouf 6 years ago from Salem MA

      That is very exciting; The Pororoca happens twice a year and is very destructive; I had NEVER heard of it before. Keep up the good work.

      Paul F

    • StefanMDP profile image
      Author

      StefanMDP 6 years ago

      Twice a year, with the full moon and the new moon.

    • profile image

      homework sucks =P 6 years ago

      hi stefan, i have done some research on "pororoca" or "the big roar", and it says that it comes once a year when the full moon rises to the west and the Atlantic Ocean tide surges into the amazon river and can go up stream 25kilometres. you can hear the wave 30 minutes before it reaches you. and they say it come between the months of feburary and march and can reach a highet of 12 feet (4 metres). please help me as i have been given information on this topic which im doing as a school research project. im getting really confused with all the different websites i have looked on. please help me.

      thanks homework sucks =P

    • StefanMDP profile image
      Author

      StefanMDP 8 years ago

      Thanks for the kind words, Ricardo.

      I'm glad that you like the Hub.

    • funride profile image

      Ricardo Nunes 8 years ago from Portugal

      Hi Stefan, great hub you got here. I can´t understand how I never found you here at HP.

      Brazil it´s a wonderful country and it´s possible to believe that our mother hearth lives there.

      Take care,

      Ricardo

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: "https://hubpages.com/privacy-policy#gdpr"

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)