[Mission 2022] QUIZ – 2022: INSIGHTS STATIC QUIZ , 4 November 2021 – Geography – INSIGHTSIAS

Solution: b)

That many of the areas of the world with high ranges of tides are in the areas of Alaska, Canada, and northern Europe has created a misconception that the range of tide increases with increasing latitude (as one moves farther from the equator and closer to the poles). This is incorrect.

Increased tidal ranges in these areas are created by the positions and configurations of the continents in the northern hemisphere. In the higher latitudes of the northern hemisphere, the continents of North America, Europe, and Asia are pressed closer together. This “constriction” of the oceans creates the effect of a higher range of tides. 

In the higher latitudes of the southern hemisphere, in the southern tips of South America, southern Africa, Australia, and Antarctica, tidal ranges are not increased. In these areas the continents are not pressed closely together, there is not a “constriction” of the oceans, and the tidal ranges are not increased.

Solution: d)

The strong gravitational pull exerted by the sun and the moon on the earth’s surface causes the tides. 

The water of the earth closer to the moon gets pulled under the influence of the moon’s gravitational force and causes high tide. 

The shape of bays and estuaries also can magnify the intensity of tides. Funnel-shaped bays in particular can dramatically alter tidal magnitude. 

• Strong offshore winds can move water away from coastlines, exaggerating low tide exposures. 
• Onshore winds may act to pile up water onto the shoreline, virtually eliminating low tide exposures. 
• High-pressure systems can depress sea levels, leading to clear sunny days with exceptionally low tides. 
• Conversely, low-pressure systems that contribute to cloudy, rainy conditions typically are associated with tides than are much higher than predicted.

Solution: b)

Harmful algal blooms, or HABs, occur when colonies of algae—simple plants that live in the sea and freshwater—grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds.

While many people call these blooms ‘red tides,’ scientists prefer the term harmful algal bloom. 

During a red tide, algae become so numerous that they discolor coastal waters (hence the name “red tide”). 

The algal bloom may also deplete oxygen in the waters and/or release toxins that may cause illness in humans and other animals. 

Major factors influencing red tide events include warm ocean surface temperatures, low salinity, high nutrient content, calm seas, and rain followed by sunny days during the summer months.