# All Questions

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23 views

### Are these igneous Liesegang rings on a popular Oahu, Hawaii hike?

I hiked the Lanikai Pillbox trail (Oahu, HI). I noticed eroded concentric rings in the igneous rock with a hard center. I'm unable to find the geologic cause of these rings. Are they Liesegang rings? ...
102 views
+50

### Snow on a relatively warm day

Outside my window it's snowing. This isn't so strange, even for the South of England in mid-April. What is surprising is that the ambient air temperatures (according to the Met-Office) are about 7 or ...
76 views

### What are the risks of developing geoengineering?

Wikipedia page for geoengineering entry list a lot of proposals to decrease global temperature: Solar radiation management methods[5] may include: Surface-based: for example, surface-based mirror ...
52 views

### Why is the Regener-Pfotzer maximum (radiation in upper atmosphere) above central California?

The site https://spaceweather.com/ has a section called Space Weather Balloon Data which shows the image below and says: The data points in the graph above correspond to the peak of the Regener-...
12 views

### Need help with MATLAB code

I am currently stuck on how to solve these questions on MATLAB. I am trying to use a for and if loop. Could I please have help please. Not sure on how to approach it Finds the year in which the ...
37 views

### What does a change in the mean pressure across 750 km indicate/signify?

Coming from the aviation site: What is the westerly index? The westerly index is: ... the Trenberth Z1 index (Trenberth 1976), which is the departure of the monthly mean pressure difference between ...
8 views

### What is the westerly index?

This was asked in aviation stack exchange and the best answer (credit:ymb1) was: The westerly index is the Trenberth Z1 index (Trenberth 1976), which is the departure of the monthly mean pressure ...
167 views

### Science behind the groundhog day myth

The myth goes that if a groundhog sees his shadow on Feb 2, six more weeks of winter are yet to come, but if he doesn't, spring is just around the corner. I am wondering if there is any science ...
3k views

### Why don't green house gases escape into space?

I have never heard an explanation as to what traps GHGs. What holds them in place? Has research been conducted to assess the efficacy of say triggering a change in their chemical composition into a ...
26 views

### Is there open scientific analysis of the proposed discharge of water from Fukushima?

Today in the news Japan has announced it will discharge water from Fukushima. All news sites I have looked at covering this give very little detail, only that about 1.4M Tonnes of water will be ...
16k views

### What caused the bend in the Emperor/Hawaii chain of islands, 45 million years ago?

What caused the bend in the Emperor/Hawaii chain of islands, 45 million years ago? Has there been any updates to this mystery I am unaware of? Are there any new theories that could potentially ...
49 views

### Seeing a varied change in brightness across the landscape during sunrise?

In this video of sunrise at Cadillac Mountain, Maine, the landscape closer to the horizon appears to brighten sooner than the foreground. It makes sense to me, the terrain at the horizon is ...
357 views

### Can clouds be formed without a pollen particle's role?

I read online that it is scientifically proven that pollen particles can trigger cloud formation "is that true"? if true ,does it mean that no clouds can be formed without pollen particles' ...
20 views

### Learn geological properties of the horizon through density of the rocks

It is possible to evaluate the geological structure of a basin based on gravimetric data. But if one doesn't have gravimetric data, how can one learn the geological structure and properties of a ...
27 views

### When it comes the average lifetime of chemicals in the atmosphere, is the mean lifetime ~1.4427 times the half-life? As with radioactivity?

There are so many websites giving numbers for 'average' lifetimes of global-warming or ozone-depleting chemicals in the atmosphere, yet they are rarely explicit in their definition(s)... For instance, ...
384 views

### The Medieval Climatic Anomaly

Trying to understand this question, posted to me by a lecturer at University: "The Medieval Climatic Anomaly was distinctive in terms of the prevailing climates and forcing mechanisms operating ...
44 views

### Prevalence of 'well-rounded' beach fabric on the Foreshore

Apologies for the vagueness of this query, but generally, would it be plausible to state that the prevalence of 'sub-rounded'* beach fabric is more common at the foreshore than 'sub-angular'* beach ...
89 views

### In cities, is the pollution level higher on higher floors?

Is there a difference between the pollution levels at higher vs lower floors in a high rise building?
17 views

### What is “small layer thickness” defined as in terms of bulk Richardson number approaching gradient Richardson number?

In may sources (https://glossary.ametsoc.org/wiki/Bulk_richardson_number), bulk Richardson number is defined as an approximation to gradient Richardson number. The prior only approaches the ladder ...
44 views

### Determining probability of precipitation from GFS data

Looking at the index files in https://ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/, there's no probability of precipitation (POP) data provided. (There is a ...
89 views

### Why should there not be water deep (e.g. below 6 kms) in the Earth's crust?

In 1970, the USSR began drilling at the Kola Super-deep Borehole. The target depth was 15,000 meters; The stated areas of study were the deep structure of the Baltic Shield, seismic discontinuities ...
63 views

### Term for the Process of the Early Earth's Crust's Changing Mineral Composition

In the book, Story of Earth-The First 4.5 Billion Years, From Stardust to Living Planet, by Robert Hazen, Chapter 3: He discusses the changing mineral composition of the early Earth's crust from ...
41 views

### Can you please identify the type of rock and whether is it natural or man-made? [closed]

I found this rock in my garden (Cheshire,UK) and wondered what type of stone it is. The two largest holes on either side go right through, almost like a bead and I wondered whether this had happened ...
58 views

### How can we distinguish fold and cycle of sedimentation on a remote sensing image or in the field?

A fold is composed of stratigraphy that is symmetric and repeated. Cyclic sediments (also called rhythmic sediments) are sequences of sedimentary rocks that are characterised by repetitive patterns of ...
65 views

### What would happen if the salt in the oceans disappeared? [closed]

Based on current understanding of how ecology processes work, what would happen in the short term as well as the long term if the salt in the Earth's oceans disappeared? why closing? i am curious to ...
59 views

### How much earth has to be moved to get one tonne of copper

I am trying to make sense of the mining process of minerals or metals. I found two measures related to waste: the stripping ratio (which is usually larger than 3:1 for copper, i.e. 3 tonnes of waste ...
3k views

### How long could a steel artifact last?

Would man-made steel artifacts be able to be preserved like fossils for millions of years, or would corrosion make them dissipate? What about metals such as aluminum that don't corrode as easily?
67 views

### Will a new glacial age take place on Earth or Holocene will become a new climatic epoch?

Pleistocene shows a switch between glacial and interglacial ages. Image source: global-climate-change.org.uk However, humanity is burning fossil fuels and increasing atmosphere's $\ce{CO2}$ content. ...
24 views

### Where can I find an anisotropic PREM-like model for Earth's interior?

So, I just discovered PREM (the Preliminary reference Earth model) which models the density distribution of matter inside the Earth to any depth. The PREM is very convenient but since it only depends ...
25 views

### When are the IPCC AR6 reports going to be published?

Im trying to find out when each of the reports from working groups 1,2 and 3 will be published due to the delay due to covid19. Does anyone have any up to date information about these dates as opposed ...
36 views

### How to identify chemical property and structure of rocks?

I am interested in identifying the properties of rocks. For example, black opal is shiny and can emit 5 different colors based on different lighting conditions. Is there a way for an amateur to be ...
112 views

### What is the characteristic time of the loss of the Earth atmosphere, how can it be calculated?

Somewhere I've read it is in the order of some tens of billions of years, but unfortunately I can't find any reference with it in Google. I suspect, the losses are coming mainly from analyzing the ...
34 views

### Salt body detection via reflection seismology

I'm supposed to plan a seismic experiment in order to detect a salt body buried under a city. From the preliminary exploration the salt body was determined to be 50m thick and 100m wide, and ...
83 views

### map projections that minimises differences

I have an odd map projection requirement, but I would like a world map projection where even very small countries, like Luxembourg or Belgium are still visible when also showing China and Canada on ...
109 views

### Why does relative humidity drop if I open the window in winter? What about the temperature drop?

I understand that 40% rel. hum. at 0 °C is less absolute humidity than 40% at 20 °C. However, assume that we have 2$~m^3$ of air. Both are 40% humid at 20 °C. Now we exchange 1$~m^3$ with air that is ...
22 views

### Differentiate correlation of between depth and bouguer anomaly

Assume we measure bouguer anomaly (g) and depth (H) of the certain horizon through a profile at each point. Based on data we get a correlation between H and g and express it with a polynomial equation ...
9 views

### Using IOS DATA unsupervised classification in Envi, how do you ensure the algorithm correctly classifies between water and dense vegetation?

I have performed an IOS DATA unsupervised classification algorithm to a Landsat scene in Envi software. Bands available are: B, G, R, NIF, SWIR plus spectral indices NDVI and NDWI. Keeping the inputs ...
47 views

### Hypothetically, in the near future, could gas hydrate pingos erupt?

Could gas hydrate pingos erupt? If so, how quickly? And how much CH4 could they release? I'm sorry if the questions sounds silly. I'm new here and I don't know much about gas hydrates and oceanography....
38 views

### How to define high frequency rainfall?

I have a rainfall data set from a weather station where the data was collected at 20 minutes intervals for 10 years. I would like to peak up the high frequency rainfall cases. What are such rainfalls? ...
79 views

### Why did the Persian Gulf shrink during the influence of Ancient Mesopotamia?

The Persian Gulf, today, looks like this. But about 4,000 years ago, it looked like this. This extended to the point where Ur, currently an inland city, was a coastal city. During this era, no other ...
18 views

### How much carbon in the surface ocean

The natural flux of carbon into the atmosphere is about 90 Gt per year. Humans are adding additional carbon dioxide each by burning fossil fuels. Some of it is absorbed by the oceans. The residence ...
283 views

### How to calculate Lifted Index from ERA5 pressure level data?

I have taken a thunderstorm case where I need to calculate indices but I am not getting any code related stability indices in Python language, the code is available in GRADS, NCL for me it's difficult ...
116 views

### It is possible to send a probe deep within the Earth?

The deepest borehole ever drilled is just 12km. Consider this as a possibility. A small self-propelled probe is created, its approximately the size of a football, and is very strong, made of materials ...
2k views

### Why are there more intense earthquakes in Iran than in Iraq?

Why are there more intense earthquakes in Iran than in Iraq, if they are so close together? I often hear news items of earthquakes in Iran that are higher on the Richter Scale than those that happen ...
40 views

### Comparing 2D fields - how do you quantify similarity?

I have a number of arrays describing both forecasts and observations of geospatial data (e.g. precipitation intensity, cloud fields...). Included are four animated gifs, each looping back and forth ...
53 views

### When does a stream become a river?

Does a stream require a certain width or volume before it can be classified as a river, and if so, what is it?
141 views

### Can there be ice in the core because of pressure?

Because there is so much pressure in the earth's core, the inner core is solid but what happens if you manage to add some water in the inner core or near it. Does the pressure make the water solid or ...
53 views

### Why are the south, the west and the north of the Caspian sea lush but its east completely dry?

About the Caspian sea area today: The south is very lush with the subtropical forests of the Iranian provinces of Gilan, Mazandaran and Golestan (although less "tropical" in Golestan) The ...