Frequently Asked Oceanography Questions

(Don't forget to ask yourself if you believe these answers! A lot of "facts" in science are more controversial than you might think...)

General

How much of the Earth's surface area is ocean?

71%. But the area of continents isn't 29%.

How deep are the oceans?

The deepest measured point is 11,020 meters, in the Marianas trench. The oceans' average depth is about 3800 meters. Here's a follow-up question for you: How would you determine these 2 numbers on your own?

What is the minimum structural, metabolic, and genetic equipment of a postprotobiont that one would consider to be a true primitive cell?

Your question relates to the origin of life, a topic that has received a lot of attention in the scientific literature, especially since the discovery of deep sea hydrothermal vents in 1977.

I think you might enjoy beginning with an article in Scientific American. There are further references therein. Here is the reference:

Title: Life's Rocky Start
Author: Robert M. Hazen
Date: April 2001
Pages: 76-86

Abstract: Air, water and rock were the only raw materials available on the early earth. The first living entitities must been fabricated from these primitive resources. New experiments suggest that minerals - the basic components of the rocks - could have played starring roles in that dramatic feat.

Atmospheric

What are " ef=http://dread.pmel.noaa.gov/~gabe/wwe/descwwe.html>westerly wind events?": Pulses of anomalously westerly (from the west) surface wind, that occur in the equatorial western pacific.

Biological

Can dolphins talk?: I don't know, but I wouldn't be surprised!

Chemical

Why are the oceans salty?: A good question! When water erodes rocks on the continents, one of the classes of minerals which is subsequently carried by the rivers to the seas is salt. When that salty water evaporates (ultimately forming the rain clouds which send fresh water down to erode more continental rocks), it leaves it's salt behind. The balance of this process with those that remove salts from the oceans (like the subduction of salt adsorbed on sediment particles) determines the saltiness of the seas.
What does the surface salinity look like in Elliot Bay?

Geological

Are any ancient hydrothermal vents visible on land due to changing sea level, uplift and/or plate movement?
Yes. Some specific slivers of oceanic crust that have been tectonically emplaced on continents above present-day sea level are generally accepted by geologists as good analogues to the parts of the sea floor that are volcanically active today. These slivers are known as "ophiolites" and much has been written about them. Interestingly, however, the ophiolites have historically been the territory of geophysicists and geologists; when microbiologists give ophiolites their full attention we may gain much more information about how ophiolites relate to ancient and present hydrothermal vents.

Who needs marine geologists, anyway?
Here's one answer for starters...

Physical

How hot is the water that comes out of deep sea volcanoes through hydrothermal vents? I'm sure at that high pressure the water can be significantly hotter than 212 degrees Farenheit. How hot is it?
Hydrothermal vent fluid gets up to about 400 degrees Celsius, or about 700 degrees Farenheit. There are many vents that have lower temperatures, but the maximum temperature is limited by the critical point of sea water at the deep sea pressures (about 200 atmospheres), the hydrothermal vent equivalent of a "boiling point."

Send your questions to us!