Damage from the 5.7 Earthquake on 03/18/2020. Source: NBC
On the morning of Wednesday, March 18th, 2020, residents of the Salt Lake Valley (SLV) in Utah were woken by a sudden jolt that traveled all over the metropolitan area. In what ended up being one of the most powerful earthquakes to hit the region in nearly 20 years, the event was then immediately followed up by hundreds of aftershocks that plagued the valley. Many residents were surprised that such a seismic event occurred in the region but the reality is that Salt Lake City and its surrounding metropolitan area is well-within one of the most seismically significant and diverse regions in the entire country. Now that the ground appears to have settled, it only feels appropriate that we dive into the science behind the Utah’s seismic zone, along with what all else may be in store for the region in the coming decades.
The intensity map for the 5.7 earthquake along with the location of the epicenter. Source: USGS
At 7:08am MDT, a 5.7 earthquake struck north-northeast of Magna, UT, and its waves soon spread over all of Salt Lake Valley . It is here that we must first distinguish what that value represents. Indeed, the commonly-known Richter scale is a measure of the amplitude and distance of an earthquake. As can be seen in figure 2, the scale is logarithmic, meaning that the amplitude of waves that are recorded during an earthquake greatly affects the output value of an earthquake. This means that a 5.0 earthquake will be much stronger than a measured 4.0 earthquake. Nevertheless, this scale fails to capture signals from larger earthquakes, resulting in underestimations of the intensity of large earthquakes . As such, newer and more modern scales are used, including the moment magnitude scale (MMS), which takes both the intensity of an earthquake and the amount of energy that is released by one.
This amount of energy is referred to by seismologists as the seismic moment, and takes into account three variables: the resistance of a rock to being bent, distance, and area. The first variable takes into account the elasticity of rock; a lower resistance results in an earthquake being able to more easily bend the rock, while a higher resistance impedes the effects of that bending. The second variable refers to the distance that the ground moved or “slipped” relative to its surroundings during the earthquake. And finally, the third variable, area, refers to the total area of the fault zone that ruptured during the earthquake. Altogether, variables that make up the seismic moment, along with the aforementioned intensity, make for a much more accurate value for the strength of a given earthquake.
The MMI therefore captures a better picture of the intensity of the shaking from an earthquake over a given area, and is what is used as the standard scale for all earthquake measurements by the USGS.
The key elements of the Richter Scale. Source: Iris
Nevertheless, the MMS should not be confused with the modified Mercalli intensity scale (MMI), which specifically measures the shaking severity of an earthquake . As we can see in figure 3, the 5.7 earthquake that occurred in SLV resulted in certain areas experiencing a large range of shaking intensity. For instance, the area around Magna experienced an MMI of 7 which translates to very strong shaking that can result in difficulty in standing and minor property damage, whereas the east side of the valley reported MMI of 5, which resulted in the movement of picture frames and door swings. As a result, the airport and several areas at and near downtown experienced strong to severe shaking that resulted in property damage and aftershocks that have continued for several days now near the original epicenter.
The Modified Mercalli Scale. Source: Geographonic
The earthquake and aforementioned aftershocks reignited a discussion about the region’s seismic zone, with questions ranging from “are earthquakes common for this area” to “when can we expect the next one”? According to the USGS, this earthquake occurred in a greater area across northern Utah that is referred to as the Intermountain Seismic Belt (ISB), with the prominent fault in the region being the Wasatch Fault that runs through downtown Salt Lake City. As can be seen in figure 5, several faults run through and near the valley, and the Magna earthquake was likely related to one of several potential known (or yet-to-be discovered) faults located on the western side of the valley. Nevertheless, the USGS warns that the Wasatch Fault and its segments are all capable of producing large earthquakes >7.0. This 5.7 would pale in comparison to the sort of damage that an earthquake of that magnitude cantered over the core of and east sides of the SLV would result in. Thankfully, such an event is highly unlikely to occur immediately following this recent earthquake but should nevertheless be expected to occur sometime in the far future. And while that nightmare scenario is unlikely at this time, smaller earthquakes of 5 and 6 are still likely to occur in the coming years, and as we saw with the damage from this recent earthquake, the shaking intensity could easily fall over a very populated area depending on the location of an epicenter. As such, now is a great time to begin discussing preventative measures that can help increase the structural integrity of buildings in the region and to spark up a conversation about earthquake safety.
The known network of faults within Salt Lake Valley. Source: Huffington Post
As the ground begins to sway, make sure that you’re aware of the things inside your home that may easily fall during severe shaking. Usually before an earthquake you’ll be able to feel initial wobbles before the jolt hits. The initial P-Waves, as they are called, travel faster from the epicenter and travel in a push-pull fashion, meaning you’ll experience some horizontal motions during the initial part of the earthquake. When you feel these movements, even if you don’t suddenly think this could be “the big one” take that time to hide under a table or to find the sturdiest location in your apartment. This method is known as: drop, cover, hold. As the S-Waves roll in, you’ll experience that jolt that results in stronger shaking. By then, you will want to be in a situation where you’ve already dropped, covered, and are holding on as the waves travel through your home . As the shaking calms down, immediately check for injuries, assess the surroundings, and if the damage in your home looks severe, get out of the home as aftershocks are very likely to occur. More information and what you should do during an earthquake can be found in the link .
The planet is alive and breathing, and while this all may sound intimidating or even slightly terrifying, it is important that we understand the science of what is happening under out feet along with the precautions that we should take in order to better handle when the next one hits. Until next time, be mindful of your surroundings and be sure to learn more about your region’s seismic vulnerabilities by checking out the USGS website.
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©2020 Meteorologist Gerardo Diaz Jr.
Mountains exist all across the world and serve a wide range of purposes from defining important landscapes to providing a plethora of opportunities for recreational activity. Additionally, they help maintain a suitable habitat for certain plant and animal life, offer beautiful views of nature, and, interestingly, can even create their own weather. When air moving across the ground reaches the base of a mountain, it is forced to move upward to the atmosphere. This lifting of air originating at the surface can eventually result in the formation of clouds and potentially even precipitation.
There are four primary atmospheric mechanisms that allow the formation of clouds to occur, each of which deals with the upward motion of air. A very common mechanism is frontal lifting. This describes the displacement of air masses (essentially large areas of the atmosphere where air shares similar qualities) over one another. Convergence refers to winds flowing in opposing directions at the surface and the subsequent upward motion of air. A third possibility, air may move vertically in the atmosphere as a result of buoyancy, as less dense relatively warm air rises above denser cold air. Lastly, a mountain or other geographic feature can provide a barrier that forces horizontally moving air upward. This process is known as orographic lift. Just as with the other three mechanisms, orographic lift can result in the formation of clouds and precipitation.
When air rises in the atmosphere as a result of any of these four primary atmospheric mechanisms, it cools. Since cold air cannot hold the large amount of water vapor warm air can, condensation of vapor into liquid droplets (and thus cloud formation) becomes much more likely to occur. Due to the higher elevation of mountain ranges, much of this cloud formation may take place near or just above the mountain top and result in the appearance of fog (essentially a cloud that has formed very close to the ground). Fog frequently settles into areas of lower elevation as relatively warm and dense air at the base of the mountain rises upward, making room for the cooler and denser fog to sink to the surface. When this physical process occurs within the context of a mountain range, the fog is referred to as valley fog. However, it is important to note that cloud formation as a result of orographic lift is not limited to the height of the mountain and may extend hundreds to even thousands of feet above the summit.
Another interesting feature of mountain weather is called a rain shadow. Rain shadows are created on the back (leeward) side of a mountain where air descends downslope. As air is pushed downward and approaches the surface, it warms and makes cloud formation unlikely to nearly impossible. The combination of downward moving air and warmer temperatures create dry atmospheric conditions unfavorable for precipitation. One well known example of this phenomenon exists on the eastern side of the Sierra Nevada mountain range, which runs directly north and south along the border of Nevada and California. Due to the extremely low elevation of the leeward side of the Sierra Nevada and the perpendicular westerly wind flow, these mountains have helped create one of the strongest rain shadows on Earth. As a result, the area on the eastern side of these mountains known as Death Valley is considered one of the hottest and driest places in all of North America.
While primarily known as a geographic feature, mountains have important meteorological impacts and influence not only short term weather, but also long term climate. From clouds that last hours to the yearly effects of low precipitation, mountains are an important part of our environment, atmosphere and ultimately, the Earth we live on.
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©2019 Weather Forecaster Dennis Weaver
Coral Reefs in Indonesia. A diversity of corals, echinoderms, sponges, and other life compete for space and plankton on the reefs surrounding Bangka Island, North Sulawesi, Indonesia, Pacific Ocean. © Ethan Daniels
According to a new research study? in the journal of Marine Ecology Progress Series, coral reefs are shifting away from the equator and are finding new reefs in more temperate regions. Researchers found that the number of young corals on tropical reefs has declined by nearly 85% and have doubled on subtropical reefs during the last four decades.
Nichole Price, a senior research scientist at Bigelow Laboratory for Ocean Sciences, said that climate change seems to be redistributing coral reefs the same way as it is shifting other marine species-and the trend is quite obvious. However, the uncertainty lies in whether the new reefs can support the incredible diversity of tropical systems. As the ocean gets warmer, subtropical environments are becoming more favourable for corals than the equatorial waters where they normally thrived. This is allowing drifting coral larvae to settle and grow in new regions. These subtropical reefs could provide refuge for other species challenged by climate change and new opportunities to protect these fledgling ecosystems.
Researchers believe that only certain types of coral are able to reach these new locations which are based on how far the microscopic larvae can swim and drift on currents before they run out of their limited fat stores. The exact composition of most new reefs is currently unknown, due to the expense of collecting genetic and species diversity data. "We are seeing ecosystems transition to new blends of species that have never coexisted, and it's not yet clear how long it takes for these systems to reach equilibrium," said Satoshi Mitarai, an associate professor at Okinawa Institute of Science and Technology Graduate University and an author of the study. "The lines are really starting to blur about what a native species is, and when ecosystems are functioning or falling apart."
New coral reefs grow when larvae settle on suitable seafloor away from the reef where they originated. The research team examined 35 degrees north and south of the equator and found that the shift of coral reefs is perfectly distributed on either side. They also looked at the location where “refugee corals” could settle in the future, potentially bringing new resources and opportunities such as fishing and tourism. The researchers, an international group from 17 institutions in six countries, compiled a global database of studies dating back to 1974, when record-keeping began. They hope that other scientists will add to the database, making it increasingly comprehensive and useful to other research questions. "The results of this paper highlight the importance of truly long-term studies documenting change in coral reef communities," said Peter Edmunds, a professor at the University of California Northridge and author of the paper. "The trends we identified in this analysis are exceptionally difficult to detect, yet of the greatest importance in understanding how reefs will change in the coming decades. As the coral reef crisis deepens, the international community will need to intensify efforts to combine and synthesize results as we have been able to accomplish with this study."
Coral reefs are intricate interconnected systems, and it is the interplay between species that enables their healthy functioning. It is unclear which other species, such as coralline algae that facilitate the survival of vulnerable coral larvae, are also expanding into new areas - or how successful young corals can be without them. Price wants to investigate the relationships and diversity of species in new reefs to understand the dynamics of these evolving ecosystems.
Some of the research that informed this study was conducted at the National Science Foundation's Moorea Coral Reef Long-Term Ecological Research site near French Polynesia, one of 28 such long-term research sites across the country and around the globe. "This report addresses the important question of whether warming waters have resulted in increases in coral populations," says David Garrison, a program director in the National Science Foundation's Division of Ocean Sciences, which funded the research. "Whether this offers hope for the sustainability of coral reefs requires more research and monitoring."
1. NN Price, S Muko, L Legendre, R Steneck, MJH van Oppen, R Albright, P Ang Jr, RC Carpenter, APY Chui, TY Fan, RD Gates, S Harii, H Kitano, H Kurihara, S Mitarai, JL Padilla-Gamiño, K Sakai, G Suzuki, PJ Edmunds. Global biogeography of coral recruitment: tropical decline and subtropical increase. Marine Ecology Progress Series, 2019; 621: 1 DOI: 10.3354/meps12980
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© 2019 Oceanographer Daneeja Mawren
Many people live near mountain chains, either on the windward side or the leeward side of the mountains. People who live on each side of the mountain can experience different weather phenomena because of a method called orographic lift.
Orographic lift is a term that defines what is happening when air rises over a land barrier, such as mountains or hills. Orographic lift is an adiabatic process, which means that all of the changes that happen within an air parcel occurs only in the parcel through changes in temperature and how much moisture can be condensed within the parcel. A parcel of air resembles a beach ball or a hot air balloon, but this is a theoretical construct where gases and particles within that parcel cannot escape it.
Air is less dense than land, so the air is forced to rise over land. As a result, the air starts to rise above the land barrier in question. As the parcel rises, the parcel cools down and condenses. The air will condense and start to form clouds when the temperature of the air equals that of the dew point. The height where the temperature and dew point are equal to each other is called the Lifted Condensation Level. People can see this when they see the base of the cloud. The air will not condense before this point and with mountain ranges, the clouds and precipitation fall on the windward side of the mountain. The windward side is the side of the mountain that the wind encounters. The land on the windward side of a mountain can be lush and green as a result of this precipitation.
On the other side of the mountain, the leeward side, the air rapidly descends and becomes warmer once more. The parcel now lacks some of the moisture that it contained on the windward side of the mountain because some of it precipitated out. As a result, the dewpoint and the temperature increased throughout its descent. The land on the leeward side of the mountain by forming an area called a ‘rain-shadow’ desert. As a rain-shadow desert implies, the land is dry due to the lack of precipitation and the higher temperatures on that side of the mountain.
So what does this mean for the people that live on each side of the mountain? Well, the climates of the windward and leeward side can vary due to the amount of precipitation in each place. This can be observed when examining the landscape of the windward and leeward side of a mountain chain. The windward side will have more vegetation because of the amount of precipitation that it receives, while the leeward side will lack that lush, green vegetation. Some rain shadow deserts can be defined as a desert-like climate as well.
This orographic lift can also be observed via satellites. Check out this Tweet from the National Weather Service in the Bay Area that depicts a rain shadow due to downsloping winds that occurred on February 26th!
The dark area in the middle of the satellite image is a ‘rain-shadow.’ The clouds are evaporating there because of the lack of moisture in that part of the region, but more clouds reform once more when it encounters the next land barrier. So even in the middle of a frontal system, orographic lift can still control which areas see precipitation.
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©2019 Weather Forecaster Shannon Sullivan
DISCUSSION: Every day in many places and regions spread around the world, there are substantial concerns tied to the ongoing threat of unpredictable landslide and/or mudslide events. Often, the biggest concerns are tied to the fact that when a given region experiences particularly heavy rainfall events over a relatively short period, there can often be a corresponding impact on both lower-level locations as well as more elevated locations in the form of a weakening of soil integrity.
More specifically, a substantially weakened soil integrity means that even with somewhat stabilizing features such as the roots of shrubs and/or trees, more saturated upper and middle soil layers can lead to there being a greater potential for landslides and/or mudslides under the corresponding and unfortunate circumstances. Moreover, when the right combination of circumstances comes into play and the threat of mudslides and landslides increases, this can lead to potential road closures, damage to local ecosystems, and even fatalities in some cases. Therefore, when there is a forecast for heavier rainfall in a region which is historically prone to landslides and/or mudslides because of heavier rainfall events, it is advisable for residents which are in the path of such threats to always heed the advice of emergency officials. In short, it is always better to get out of harms way than to try to figure out a clever way to get around such threats just by generating what is thought to be enough protection from such threats.
Moreover, depending on the type of soil composition in place within a given region, a given landslide or mudslide event can behave differently in terms of their total spatial extent and their impact reach from start to finish. Thus, in a world where rainfall events and precipitation totals in atmospheric events such as (but certainly not limited to) tropical cyclones are expected to likely become more extreme as time moves forward, there is a correspondingly increasing threat for the occurrence of such events and people should always take respective threats as serious as local officials and scientists are suggesting they may be under certain circumstances. The moral of this story is to always take geological threats such as landslides and mudslides as real as the threats always appear to be and never underestimate the power of falling rock and soil regardless of the exact steepness of a given slope.
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© 2019 Meteorologist Jordan Rabinowitz
Weather, Leaves, and Fall Foliage (credit: How Stuff Works, ThoughtCo, Durango Train, The Weather Channel, Smoky Mountains)
Image: Vibrant fall foliage - Credit ThoughtCo.
Discussion: Fall is here and that means it’s time to say goodbye to green leaves. Already, some areas in the Northern Hemisphere are seeing changes in leaf foliage. Temperature, sunlight, and soil moisture are key factors that determine the boldness and vibrancy of fall leaf colors. Spring and fall weather are key. Since leaves grow in the spring, wetter springs are ideal. In the fall, warm and sunny days paired with cool and dry nights yield colorful leaf foliage. Soil moisture in the spring and summer can help increase chances for a picturesque fall, though summer weather itself does not have a substantial impact on the fall foliage.
Image: Chlorophyll depicted in a leaf - Credit Smoky Mountains.
Chlorophyll is the plant molecule responsible for giving a leaf it’s green color. Leaves house other pigments as well,but chlorophyll masks them throughout most of the year. A shorter amount of daylight is the main cause for leaf color change. In the fall, when chlorophyll levels decrease, pigments of yellow by xanthophyll and orange by carotene are more visible. Photosynthesis is the process in which leaves interact with carbon dioxide and water to produce sugars and oxygen. When sugar is trapped in the leaf by the tree’s sealant, red and purple from anthocyanin pigment dominate. Cool nighttime air accompanied by daytime sunshine enhances red and purple colors.
Image: Fall foliage - Credit ThoughtCo.
Leaves will fall before fully developing color if the growing season is dry, there is early frost, heavy rain, or extreme wind eventsin the fall. Elevation and latitude also affect how early the leaves change. High elevations such as Denver, CO and/or higher latitudes such as Boston, MA will see earlier peak times and therefore falling of leaves.
Image: Fall 2018 foliage peak times - Credit The Weather Channel.
The Weather Channel recently explained the typical peak of fall foliage across the Continental U.S. Overall, the leaves change quicker in higher latitudes and elevations. In late September or early October, fall colors reach their peak in the highly elevated Rockies, as well as northern Minnesota, northern Wisconsin, norther Michigan, northern Pennsylvania, upstate New York, and northern New England in higher latitudes. Fall colors typically peak in the second half of October throughout the western region, Midwest into the South, and the majority of the Northeast. Sometimes the mid-Atlantic and Southeast coasts and parts of the Deep South are slow to peak. If that is the case this year, the leaves will peak in early November.
Image: Fallen leaves on the ground - Credit How Stuff Works.
Once this process is over, we usually forget about leaves until they bud again in the springtime. In actuality, leaves undergo a full cycle. After leaves fall, they decompose and create a rich humus, or dirt, on the ground that absorbs dew and rainfall. The fallen leaves are nutrient rich and act as sponges providing continual sources of nutrients and water to trees and other plants. In this way, leaves continually work as the life cycle ensures health and sustainability for trees until they sprout again the following spring.
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© 2018 Meteorologist Amber Liggett
DISCUSSION: Kilauea volcano on Hawai’i island is an active volcano with continuous eruptions dating to 1983. May 3rd, 2018 was the most current volcanic eruption cycle for Kilauea, opening fissures in Leilani Estates, Lanipuna Gardens, with an estimated 22 fissures having opened as recent as Monday, May 21st 2018 in Puna. To no surprise, due to this increase in volcanic activity this has brought about the influx of information given by the USGS (U.S. Geological Survey) to residents and new questions that prompt aid now from the NWS (National Weather Service).
According to the USGS, “Geology efforts address major societal issues that involve geologic hazards and disasters, climate variability and change, energy and mineral resources, ecosystem and human health, and ground-water availability.” With this, it is to be expected that the USGS and geologists alike are studying the impacts of the most recent fissures and eruption cycle of Kilauea. In addition to such work with monitoring the East Rift Zone activity, advance of lava flows, earthquake activity, such a localized volcanic event has also produced ashfall, gas emissions and are thus warning residents of potential hazards associated with Kilauea. However such hazards come with observational limitations that the USGS cannot resolve.
Queue the NWS and it’s team of meteorologists and atmospheric scientists.
The NWS states, “meteorology is the science concerned with the Earth’s atmosphere and it’s physical processes. A meteorologist is a physical scientist who observes, studies, or forecasts the weather.” While not entirely obvious as to why the NWS is needed during this current eruption, Geologists often observe the geologic feature (here being Kilauea), the hazard of this volcano, its transformation, significance, relation to seismic activity, and advancement of lava flows, however once the eruption reaches the troposphere, (the lowest layer of Earth’s atmosphere extending approximately 10 kilometers) the issue at hand becomes one for a meteorologist. The troposphere is the layer humans live in, with nearly all weather occurring in the troposphere. This is of interest as once a volcano such as Kilauea erupts, ashfall becomes a potential hazard for residents, including the increase of particulate matter into the atmosphere this brings concern for acidic rainfall, and redirection of flight patterns in and around the Hawaiian Islands as trade winds and the jet stream influence lower and upper level wind movement of the particulate matter.
This most recent volcanic activity has allowed for the coordination of geologists and meteorologists to provide residents in the East Rift zone with information on fissures, gas emissions, Vog (volcanic smog), lava inundation, ashfall propagation, and any advisories/watches/warnings associated with Kilauea.
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© 2018 Meteorologist Jessica Olsen
DISCUSSION: On May 3, the Island of Hawaii experienced the beginning of a major episode of the ongoing eruption of Mount Kilauea. Mount Kilauea has been actively erupting since January 3, 1983. Mount Kilauea is a shield volcano and generally erupts from the sides in small pockets called rift zones instead of straight through the top as one imagines a stereotypical volcanic eruption such as Mt. St. Helens. This latest episode is happening on the east rift zone of the volcano.
In recent days, this episode has increased ash production which is a danger to aircraft. Volcanic ash is a major problem for plane engines as the ash is known to damage the blades. In addition, the volcanic ash can contaminate the fuel which forces the engine to work harder increasing fuel consumption. In addition, the ash has reached up to 30,000 feet which would allow it to reach places such as central Mexico where it would worsen air quality. However, many of the major ash explosions have only reached an elevation of 10,000 feet. As a result, much of the ash is distributed over parts of the far east shore of the island of Hawaii and into the Pacific Ocean.
In addition to the ash, chemicals emitted from the volcano, most notably sulfur dioxide, has caused problems in the air quality for the Island of Hawaii. One of the problems with the sulfur dioxide is the creation of vog. Vog is a portmanteau of volcanic fog as it is formed from the interaction of water vapor with the volcanic emissions including sulfur dioxide. Another concern involved with the sulfur dioxide being emitted, is the formation of acid rain, which is very dangerous as acid rain can destroy trees and property. The concern of acid rain is mainly localized on the far east coast of the island of Hawaii and may even be a concern for the major city of Hilo if there is a wind shift to a southerly-southeasterly flow at low levels of the atmosphere. However, the west side of the island including Kona is not being affected as much as usual because the wind flow is the prevailing trade winds which come from the northeast.
The eruption has destroyed 37 buildings with only one injury reported. More damage is possible if many more fissures open in the rift. In addition, the emissions of sulfur oxides and methane will continue to be an air quality issue for a few weeks as it would take a while for the chemicals to clear up and be less concentrated.
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© 2018 Meteorologist JP Kalb
DISCUSSION: Ever since the Earth formed, many people around the world have continued to remain intrigued by how new islands form as the Earth has evolved. The key answer to this question often lies in certain places near the bottom of various oceanic basins around the world. At locations wherein there is an underwater volcano, such places are known as hot-spots. Hot-spots are effectively locations at which new land can form due to underwater volcanic eruptions ejecting volcanic material close to (if not right up to) the surface of the ocean above where the given eruption occurred. Thus, given the right sub- and surface-based oceanic conditions, new islands can form over the course of time.
It is worth noting the fact that underwater hot-spots were responsible for forming island chains around the world such as (but certainly not limited to) Hawaii. Thus, hot-spots provide a unique and viable method by which new islands and island chains can and do form in different parts of the world over very long periods of time. It is also important to note that such processes take a long time, so anyone interested in moving to a newer, developing island should not exactly "buy stock" in future building developments on these "growing islands" since it can often take centuries and even millennia until such islands are remotely ready to start being inhabited in any capacity. Thus, even though the premise of new islands forming in your lifetime may sound enticing, this does not always correlate to what you may think it will within a given lifetime.
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© 2018 Meteorologist Jordan Rabinowitz
If you have been keeping up with the Geosciences section, you may know that the last two months, the climate of the Triassic period and the Jurassic period were covered, in a mini-series designed to look at the climate of the different periods of the Mesozoic era. Now, a closer look at the last period in the Mesozoic era, the Cretaceous period (145 – 65 million years ago), will be reviewed.
The early Cretaceous was not much different than the late Jurassic. Sea levels continued to rise as continents continued to move, and tectonic plates continued to shift. As was happening in the Jurassic period, dinosaurs were evolving independent of one another, and becoming more and more specialized. One of these specialized predators includes the infamous Tyrannosaurus Rex.
Vegetation wise, the first of the angiosperms (flowering plants) started to grow. These plants started off small and weedy during the early Cretaceous, but by the late Cretaceous, large flowers had begun to form. These angiosperms had allowed a lot of grazing dinosaurs, like Triceratops, to flourish.
The end of the Cretaceous also saw a rise in today’s dominant life form: mammals. None of the mammals got any larger than a cat or small dog, most being mouse- or rat-size. Another evolution seen in the Cretaceous were small reptiles and amphibians, such as salamanders, turtles, or lizards.
It was also the end of the Cretaceous that changes in climate would start dramatically affecting future life on earth. Sea levels started to fall again, and temperatures started to lower. Volcanic activity was also occurring, causing a global cooling.
From here, the story is one we all know the ending to: A large asteroid collided with Earth, and more than half of the world’s animals, including the dinosaurs, went extinct. Despite this melancholy ending, the dinosaurs still remain some of the most fascinating creatures, and by looking at the climate of the Mesozoic era, a better understanding of them can be appreciated.
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© 2018 Weather Forecaster Joseph Fogarty