How to Identify Trees With Leaves

How to Identify Trees With Leaves Would you like to learn how to identify trees in your local community? The best place to get started is by looking at the trees foliage.   Trees With Leaves This is a big category, so lets break it down into two main groups: Trees with needles or scale-like leaves.  Cedar and juniper trees have scale-like leaves that look more like flattened out fans than either leaves or needles.  Cedar  trees have green scales and small cones.  Junipers, on the other hand, have bluish, berry-like cones. Trees with leaves.  To make things simpler, we are once again going to break this category into two groups. Trees With Simple Leaves These trees have one leaf attached to each stem. Leaves with a consistent leaf edge are called unlobed leaves while trees with leaves that form shapes along their margins are called lobed leaves.  If your tree has unlobed leaves, you must next determine whether or not it has teeth - or serrations around its margin. Unlobed and smooth (no teeth).  Magnolia  have large, glossy green leaves with rust-colored hairs on the under-surface.  Live oaks  have long slender deciduous leaves and small acorns.  Dogwoods  have wavy edges and 6-7 veins that pattern either side of the leafs midrib. If your tree has leaves that are oblong or elliptical and appear crowded on short branches, it might be a  Blackgum.  And if its leaves are thick and pointed, it might be a  Persimmon.Unlobed and serrated.  Willow  trees have long skinny leaves.  Basswood  trees have wide leaves with coarse teeth and a notched area around the stem.  Elm  trees are asymmetrical at the stem and double serrations around the edge. If your trees leaves are soft and shiny with teeth that curve in from the surface, it is probably a  Beech.  If its leaves are heart-shaped with double serrations, it is likely a  Birch. And if it has elliptical leaves with jagged edges, it is probably a  Cherry.  Ã‚  Lob ed. If your tree had leaves with different lobe patterns on the same tree, it is probably a  Ã¢â‚¬â€¹Sassafrass  or a  Mulberry.  If the lobes seem to radiate from a central point like fingers on a hand, it is called palmate and it is a maple, sweetgum, sycamore, or poplar.  Maple  trees have three to four lobes and are arranged opposite of one another on the branch.  Sycamore  trees have big leaves that are larger than four inches with shallow lobes and alternating (not directly across from one another,) on the branch. Trees with star-shaped leaves with pointed lobes are likely  Sweetgums.  And leaves that look like they have been cut off or flattened at the top with two lobes on other side of the mid-rib are probably  Poplars. If the lobes appear to radiate from several points along the midrib, the leaves are considered pinnate and it is either an oak or a holly tree.  White Oak  trees have lobes that are rounded along the edges and no spines.  Red Oakà ‚  leaves are rounded at the base but jagged or spiny along the edges. And  Holly  trees have small red berries and leaves with sharp, pointed lobes. Trees With Compound Leaves Palmately compound leaves. Trees in this category have multiple leaves that appear to grow from the same point on the stalk.  Buckeye  trees have long leaves with jagged saw-toothed edges while Horsechestnut  trees have shiny nuts and seven leaflets that turn yellow in the fall.Pinnately compound leaves. Trees with that have pinnate compound leaves have leaflets that grow from multiple points along the stem. Leaves that appear doubly compound (leaflets within leaflets,) are likely  Locust  trees.  Hickory  trees have nine blades that are uneven in size and alternate along the stem.  Ash  trees have leaflets that are opposite from one another along the stem and are the same shape and size. Walnut  trees have 9-21 pointed leaflets that alternate along the stem.  And  Pecan trees have 11-17 curved, sickle-shaped leaflets that alternate along the stem.

Learn the Basics of Earthquakes

Learn the Basics of Earthquakes Earthquakes are natural ground motions caused as the Earth releases energy. The science of earthquakes is seismology, study of shaking in scientific Greek. Earthquake energy comes from the stresses of plate tectonics. As plates move, the rocks on their edges deform and take up strain until the weakest point, a fault, ruptures, and releases the strain. Earthquake Types and Motions Earthquake events come in three basic types, matching the three basic types of fault. The fault motion during earthquakes is called slip or coseismic slip. Strike-slip events involve sideways motion- that is, the slip is in the direction of the faults strike, the line it makes on the ground surface. They may be right-lateral (dextral) or left-lateral (sinistral), which you tell by seeing which way the land moves on the other side of the fault.Normal events involve downward movement on a sloping fault as the faults two sides move apart. They signify extension or stretching of the Earths crust.Reverse or thrust events involve upward movement, instead, as the faults two sides move together. Reverse motion is steeper than a 45-degree slope, and thrust motion is shallower than 45 degrees. They signify compression of the crust. Earthquakes can have an oblique slip that combines these motions. Earthquakes dont always break the ground surface. When they do, their slip creates an offset. Horizontal offset is called heave and vertical offset is called throw. The actual path of fault motion over time, including its velocity and acceleration, is called fling. Slip that occurs after a quake is called postseismic slip. Finally, slow slip that occurs without an earthquake is called creep. Seismic Rupture The underground point where the earthquake rupture begins is the focus or hypocenter. The epicenter of an earthquake is the point on the ground directly above the focus. Earthquakes rupture a large zone of a fault around the focus. This rupture zone may be lopsided or symmetrical. Rupture may spread outward evenly from a central point (radially), or from one end of the rupture zone to the other (laterally), or in irregular jumps. These differences partly control the effects that an earthquake has at the surface. The size of the rupture zone- that is, the area of fault surface that ruptures- is what determines the magnitude of an earthquake. Seismologists map rupture zones by mapping the extent of aftershocks. Seismic Waves and Data Seismic energy spreads from the focus in three different forms: Compression waves, exactly like sound waves (P waves)Shear waves, like waves in a shaken jump rope (S waves)Surface waves resembling water waves (Rayleigh waves) or sideways shear waves (Love waves) P and S waves are body waves that travel deep in the Earth before rising to the surface. P waves always arrive first and do little or no damage. S waves travel about half as fast and may cause damage. Surface waves are slower still and cause the majority of the damage. To judge the rough distance to a quake, the time the gap between the P-wave thump and the S-wave jiggle and multiply the number of seconds by 5 (for miles) or 8 (for kilometers). Seismographs are instruments that make seismograms or recordings of seismic waves. Strong-motion seismograms are made with rugged seismographs in buildings and other structures. Strong-motion data can be plugged into engineering models, to test a structure before it is built. Earthquake magnitudes are determined from body waves recorded by sensitive seismographs. Seismic data is our best tool for probing the deep structure of the Earth. Seismic Measures Seismic intensity measures how bad an earthquake is, that is, how severe shaking is at a given place. The 12-point Mercalli scale is an intensity scale. Intensity is important for engineers and planners. Seismic magnitude measures how big an earthquake is, that is, how much energy is released in seismic waves. Local or Richter magnitude ML is based on measurements of how much the ground moves and moment magnitude Mo is a more sophisticated calculation based on body waves. Magnitudes are used by seismologists and the news media. The focal mechanism beachball diagram sums up the slip motion and the faults orientation. Earthquake Patterns Earthquakes cannot be predicted, but they have some patterns. Sometimes foreshocks precede quakes, though they look just like ordinary quakes. But every large event has a cluster of smaller aftershocks, which follow well-known statistics and can be forecasted. Plate tectonics successfully explains where earthquakes are likely to occur. Given good geologic mapping and a long history of observations, quakes can be forecasted in a general sense, and hazard maps can be made showing what degree of shaking a given place can expect over the average life of a building. Seismologists are making and testing theories of earthquake prediction. Experimental forecasts are beginning to show modest but significant success at pointing out impending seismicity over periods of months. These scientific triumphs are many years from practical use. Large quakes make surface waves that may trigger smaller quakes great distances away. They also change stresses nearby and affect future quakes. Earthquake Effects Earthquakes cause two major effects: shaking and slip. Surface offset in the largest quakes can reach more than 10 meters. Slip that occurs underwater can create tsunamis. Earthquakes cause damage in several ways: Ground offset can cut lifelines that cross faults: tunnels, highways, railroads, powerlines, and water mains.Shaking is the greatest threat. Modern buildings can handle it well through earthquake engineering, but older structures are prone to damage.Liquefaction occurs when shaking turns the solid ground into mud.Aftershocks can finish off structures damaged by the main shock.Subsidence can disrupt lifelines and harbors; invasion by the sea can destroy forests and croplands. Earthquake Preparation and Mitigation Earthquakes cannot be predicted, but they can be foreseen. Preparedness saves misery; earthquake insurance and conducting earthquake drills are examples. Mitigation saves lives; strengthening buildings is an example. Both can be done by households, companies, neighborhoods, cities, and regions. These things require a sustained commitment of funding and human effort, but that can be hard when large earthquakes may not occur for decades or even centuries in the future. Support for Science The history of earthquake science follows notable earthquakes. Support for research surges after major quakes and is strong while memories are fresh but gradually dwindles until the next Big One. Citizens should ensure steady support for research and related activities like geologic mapping, long-term monitoring programs, and strong academic departments. Other good earthquake policies include retrofitting bonds, strong building codes and zoning ordinances, school curricula, and personal awareness.