Height from sea level

This site was designed to help you find the height above sea level of your current location, or any point on Earth. When viewed from a phone that supports altitude readings, the reading will come directly from your device altitude reading and will update automatically as you move. From a computer your elevation is loaded from our API based on your location.The elevation map also supports dragging the location pin on the map to search for nearby locations. You can also use the search bar to find any location in the world.Why use an elevation map?An elevation map is a topographical map that shows the height of the land above sea level. Elevation maps are also used by hikers and backpackers to determine the difficulty of a hike. Elevation maps are also used by surveyors to determine the elevation of a plot of land.What is elevation?Elevation is a measurement of height above sea level. Elevation typically refers to the height of a point on the earth’s surface, and not in the air. Altitude is a measurement of an object’s height, often referring to your height above the ground (such as in an airplane or a satellite). While elevation is often the preferred term for the height of your current location, altitude and height above sea level are also common.How do you find your elevation?Using this website you can find out your elevation no matter where you are. How does this site determine your precise elevation? The site receives GPS data

This site was designed to help you find the height above sea level of your current location, or any point on Earth. When viewed from a phone that supports altitude readings, the reading will come directly from your device altitude reading and will update automatically as you move. It will even work when your phone is offline. From a computer your elevation is loaded from our API based on your location.What is elevation?Elevation is a measurement of height above sea level. Elevation typically refers to the height of a point on the earth’s surface, and not in the air. Altitude is a measurement of an object’s height, often referring to your height above the ground (such as in an airplane or a satellite). While elevation is often the preferred term for the height of your current location, altitude and height above sea level are also common.How is elevation calculated?Using an AltimeterAn altimeter is an instrument used to measure altitude. Altitude is measured with an altimeter by calculating differences in atmospheric pressure. Inside of an altimeter is a barometer which is a device that measures pressure in the air. As you travel upwards, the pressure decreases which causes the bellows inside the barometer to expand. The bellows then give you an accurate reading of your height above sea level regardless of whether you are on the ground, in a tree, or in an airplane. Modern smartphones contain a barometer that can be used as an altimeter to measure elevation or to calculate the number of steps you have climbed.In areas with poor GPS reception an altimeter can be more accurate than GPS-based elevation readings and do not require an Internet connection.Using a Digital Elevation ModelSatellite data from NASA and other public agencies can be combined to create what is called a DEM or Digital Elevation Model which is a detailed list of elevation values for points on the Earth’s surface. You can then use GPS to fetch the value elevation reading in the DEM.When we look at representations of the earth we typically see a perfectly circular sphere. But the reality is that the surface of the earth is rather corrugated, rugged and irregular. These irregularities and variations in the earth’s surface determine the acceleration of gravity, which vicariously creates the shape of the earth’s liquids. If we were to hypothetically subtract winds, tides and other external forces that alter bodies of water we would be left with something known as the geoid. It is the shape that the Earth’s surface would take if it were all one big ocean without winds or tides. The geoid is purely hypothetical though, but it is used as a reference for land surveyors to determine elevation based on what the sea-level would have been for a given point on Earth without land. This is also referred to as “height above mean sea level”.The planet earth is extremely large and has radically diverse elevations. For example, the highest point on earth is Mt. Everest, which

What is a Vertical Datum? When the Federal Emergency Management Agency (FEMA) assesses the possibility of a 100-year flood and states that floodwaters will rise 25 feet… …what exactly is “25 feet” referenced to? We need a consistent starting point to compare flood and ground elevations. Enter the vertical datum. Surveyors, geodesists, and insurers use the vertical datum as a surface of zero elevation to which heights can be referred.Tidal Datums vs Vertical Geodetic DatumsWhen you talk about vertical datums, you can break them into two:TIDAL DATUMS reflect the interface between water and land and are defined by the tidal variation. For example, a tide gauge in the water measures mean sea level. Tidal datums are localized because the transition between types of datums can shift quickly. It’s also time-dependent. Installing a Tide Gauge | Image Credit: NOAAGEODETIC DATUMS are reference surfaces of zero elevation to which heights are referred to over a large geographic extent. These datums are used to measure the height (altitude) and depth (depression) above and below mean sea level. Commonly used vertical datums in North America are the National Geodetic Vertical Datum of 1929 (NGVD29) and the North American Vertical Datum of 1988 (NAVD88).A (vertical) geodetic datum often ties in tidal datums. A geodetic datum reference might use a tidal datum as a starting point. If you think about it, a community’s height system should be consistent with a tidal datum because that’s where the water will flow.Types of Reference HeightsThere are different types of heights to be aware of when referring to a vertical datum. These are the 3 primary types of heights, although other types of heights exist: ORTHOMETRIC represents the height distance between the Earth’s surface and geoid at a specific point. Surveyors usually refer to orthometric heights. When you take the height at the peak of a mountain. It’s an orthometric height measured as the distance between the surface and the geoid.GEOID coincides with mean sea level as if you are imagining it as an extension under (or over) land areas. The geoid is an equipotential surface at which gravity is normal – closely approximating mean sea level. This is because of the varying densities that are present on the Earth at different places. There are gravity anomalies with undulations differing from place to place.Land and mountains prevent us from seeing the geoid surface of the Earth. The Earth’s interior differs